CN112470491A

CN112470491A - Bone conduction loudspeaker and testing method thereof

Info

Publication number: CN112470491A
Application number: CN201980039998.7A
Authority: CN
Inventors: 郑金波; 廖风云; 张磊; 齐心
Original assignee: Shenzhen Voxtech Co Ltd
Current assignee: Shenzhen Voxtech Co Ltd
Priority date: 2018-06-15
Filing date: 2019-01-05
Publication date: 2021-03-09
Anticipated expiration: 2039-01-05
Also published as: CN110611853A; PE20210778A1; MX2020013708A; CN110611853B; CO2021000022A2; KR20210020122A; US11115751B2; AU2019285890A1; CN110611873A; JP2021527365A; CL2020003228A1; CN116996820A; CA3103582A1; CN110611873B; CN114786102A; EP3793214A4; EP3793214A1; BR112020025568A2; AU2019285890B2; CN114866930A

Abstract

The embodiment of the application discloses a bone conduction loudspeaker and a testing method thereof. The bone conduction speaker includes: a magnetic circuit assembly for providing a magnetic field; a vibration assembly, at least a portion of which is located in the magnetic field, converting an electrical signal input to the vibration assembly into a mechanical vibration signal; a case including a case panel facing a human body side and a case back side opposite to the case panel, the case accommodating the vibration component, the vibration of the case back side having a second phase, wherein an absolute value of a difference between the first phase and the second phase is less than 60 degrees when a frequency of the vibration of the case panel and a frequency of the vibration of the case back side are 2000Hz to 3000 Hz. The bone conduction speaker of this application can show and reduce lou sound, improves tone quality. And the structure is simpler and the size is smaller.

Description

Bone conduction loudspeaker and testing method thereof

This application claims priority to chinese application No. 201810624043.5 filed on 15/06/2018, the entire contents of which are incorporated herein by reference.

Technical Field

The application relates to the field of bone conduction earphones, in particular to a bone conduction loudspeaker capable of improving tone quality and sound leakage problems and a testing method thereof.

Background

The bone conduction loudspeaker can convert the electric signal into a mechanical vibration signal, and the mechanical vibration signal is transmitted into auditory nerves of a human body through human tissues and bones, so that a wearer can hear the sound. Because the bone conduction speaker transmits sound through mechanical vibration, when the bone conduction speaker works, surrounding air can be driven to vibrate, and the problem of sound leakage is caused. The application provides a simple structure, small and exquisite bone conduction speaker, its sound leakage that not only can show to reduce bone conduction earphone can improve bone conduction earphone's tone quality moreover.

Disclosure of Invention

The invention aims to provide a bone conduction speaker, which aims to simplify the structure of the bone conduction speaker, reduce sound leakage and improve the sound quality.

In order to achieve the purpose of the invention, the technical scheme provided by the invention is as follows:

a bone conduction speaker, comprising: a magnetic circuit assembly for providing a magnetic field; a vibration assembly, at least a portion of which is located in the magnetic field, converting an electrical signal input to the vibration assembly into a mechanical vibration signal; a housing comprising a shell panel on a side facing a human body and a shell back side opposite the shell panel, the housing containing the vibratory assembly, the vibratory assembly causing the shell panel and the shell back side to vibrate, the vibration of the shell panel having a first phase and the vibration of the shell back side having a second phase, wherein the absolute value of the difference between the first phase and the second phase is less than 60 degrees at a frequency of 2000Hz to 3000Hz for the vibration of the shell panel and the vibration of the shell back side.

In some embodiments, the vibrations of the housing panel have a first amplitude and the vibrations of the housing back have a second amplitude, and a ratio of the first amplitude to the second amplitude is in a range of 0.5 to 1.5.

In some embodiments, the vibration of the housing panel produces a first leakage sound wave, the vibration of the housing back produces a second leakage sound wave, the first and second leakage sound waves are superimposed on each other, the superimposition reduces the amplitude of the first leakage sound wave.

In some embodiments, the housing face plate and the housing back face are made of a material having a young's modulus greater than 4000 Mpa.

In some embodiments, the difference in area of the housing panel and the housing back does not exceed 30% of the housing panel area.

In some embodiments, the bone conduction speaker further comprises a first element, wherein the vibration assembly is connected with the housing through the first element, and the young's modulus of the first element is greater than 4000 Mpa.

In some embodiments, the housing panel is connected to the rest of the housing by one or a combination of any of glue, snap, weld, or screw connection.

In some embodiments, the housing panel and the housing back are made of a fiber reinforced plastic material.

In some embodiments, the bone conduction speaker further comprises an earphone fixing assembly for holding the bone conduction speaker in stable contact with a human body; and the earphone fixing component is fixedly connected with the bone conduction loudspeaker through an elastic component.

In some embodiments, the bone conduction speaker produces two low frequency resonance peaks in a frequency range of less than 500 Hz.

In some embodiments, the two low frequency resonance peaks relate to the modulus of elasticity of the vibration component and the earpiece fixation component.

In some embodiments, the two low frequency resonance peaks generated in the frequency range of less than 500Hz correspond to the earphone fixing component and the vibration component, respectively.

In some embodiments, the bone conduction speaker produces at least two high frequency resonance peaks in a frequency range greater than 2000Hz that are related to the modulus of elasticity of the housing, the volume of the housing, the stiffness of the housing panel, and/or the stiffness of the housing back.

In some embodiments, the vibration assembly includes a coil and a vibration transmitting plate; at least a portion of the coil is located within the magnetic field and is driven in motion within the magnetic field by an electrical signal.

In some embodiments, one end of the vibration-transmitting plate is in contact with an inner surface of the case, and the other end of the vibration-transmitting plate is in contact with the magnetic circuit assembly.

In some embodiments, the bone conduction speaker further comprises a first element, wherein the coil is connected with the housing through the first element, and the first element is made of a material having a young's modulus of more than 4000 Mpa.

In some embodiments, the bone conduction speaker further comprises a second element, wherein the magnetic circuit system is connected with the housing through the second element, and the elastic modulus of the first element is greater than the elastic modulus of the second element.

In some embodiments, the second element is a vibration transfer plate, which is an elastic member.

In some embodiments, the vibration transmission sheet is a three-dimensional structure and can perform mechanical vibration in a thickness space of the vibration transmission sheet.

In some embodiments, the magnetic circuit assembly comprises a first magnetic element, a first magnetically permeable element, and a second magnetically permeable element; the lower surface of the first magnetic conduction element is connected with the upper surface of the first magnetic element; the upper surface of the second magnetic conduction element is connected with the lower surface of the first magnetic element; the second magnetic conducting element is provided with a groove, the first magnetic element and the first magnetic conducting element are fixed in the groove, and a magnetic gap is formed between the first magnetic element and the side surface of the second magnetic conducting element.

In some embodiments, the magnetic circuit assembly further comprises a second magnetic element; the second magnetic element is arranged above the first magnetic conduction element, and the magnetization directions of the second magnetic element and the first magnetic element are opposite.

In some embodiments, the magnetic circuit assembly further comprises a third magnetic element; the third magnetic element is arranged below the second magnetic conduction element, and the magnetization directions of the third magnetic element and the first magnetic element are opposite.

A method of testing a bone conduction speaker, comprising: sending a test signal to a bone conduction speaker, the bone conduction speaker comprising a vibration component and a housing containing the vibration component, the housing comprising a housing faceplate and a housing backplate located on either side of the vibration component, respectively, the vibration component causing vibration of the housing faceplate and the housing back based on the test signal; acquiring a first vibration signal corresponding to vibration of the housing panel; acquiring a second vibration signal corresponding to the vibration of the back of the shell; and determining a phase difference of the vibration of the case panel and the vibration of the case back based on the first vibration signal and the second vibration signal.

In some embodiments, determining a phase difference of the vibration of the housing panel and the vibration of the housing back based on the first vibration signal and the second vibration signal comprises: acquiring the waveform of the first vibration signal and the waveform of the second vibration signal; and determining the phase difference based on the waveform of the first vibration signal and the waveform of the second vibration signal.

In some embodiments, determining a phase difference of the vibration of the housing panel and the vibration of the housing back based on the first vibration signal and the second vibration signal comprises: determining a first phase of the first vibration signal based on the first vibration signal and the test signal; determining a second phase of the second vibration signal based on the second vibration signal and the test signal; and determining the phase difference based on the first phase and the second phase.

In some embodiments, the test signal is a sinusoidal periodic signal.

In some embodiments, obtaining a first vibration signal corresponding to vibration of the housing panel comprises: emitting a first laser to an outer surface of the housing panel; receiving first reflected laser light generated by reflecting the first laser light by the outer surface of the shell panel; determining the first vibration signal based on the first reflected laser light.

In some embodiments, acquiring a second vibration signal corresponding to vibration of the back side of the housing includes: emitting a second laser light to an outer surface of the back side of the housing; receiving second reflected laser generated by reflecting the second laser by the outer surface of the back surface of the shell; determining the second vibration signal based on the second reflected laser light.

A bone conduction speaker, comprising: a magnetic circuit assembly for providing a magnetic field; a vibration assembly, at least a portion of which is located in the magnetic field, converting an electrical signal input to the vibration assembly into a mechanical vibration signal; a housing containing the vibration assembly; and an earphone fixing member fixedly connected to the housing for maintaining the bone conduction speaker in contact with the human body, wherein the housing has a housing panel facing one side of the human body and a housing back face opposite to the housing panel, and a housing side face between the housing panel and the housing back face, and the vibration member causes the housing panel and the housing back face to vibrate.

In some embodiments, the housing back and the housing sides are of integrally formed construction; the shell panel is connected with the side face of the shell through one or the combination of any more of glue, clamping, welding or threaded connection.

In some embodiments, the housing panel and the housing side are of unitary construction; the back of the shell is connected with the side face of the shell through one or the combination of any more of glue, clamping, welding or threaded connection.

In some embodiments, the bone conduction speaker further comprises a first element, wherein the vibration assembly is connected to the housing through the first element.

In some embodiments, the housing side and the first member are a unitary structure; the shell panel is connected with the outer surface of the first element through one or the combination of any more of glue, clamping, welding or threaded connection; the back of the shell is connected with the side of the shell through one or the combination of any more of glue, clamping, welding or threaded connection.

In some embodiments, the earphone securing assembly and the back of the housing or the side of the housing are of an integrally molded construction.

In some embodiments, the earphone fixing component is connected with the back surface of the housing or the side surface of the housing through one or a combination of any more of glue, clamping, welding or threaded connection.

In some embodiments, the housing is a cylinder, and the housing panel and the housing back are upper and lower end surfaces of the cylinder, respectively; and the projected areas of the housing panel and the housing back surface on the cross section perpendicular to the axis of the column are equal.

In some embodiments, the vibration of the housing panel has a first phase and the vibration of the housing back has a second phase; the absolute value of the difference between the first phase and the second phase is less than 60 degrees when the vibration frequency of the case panel and the vibration frequency of the case back are 2000Hz to 3000 Hz.

In some embodiments, the vibrations of the housing panel and the vibrations of the housing back comprise vibrations having a frequency within 2000Hz to 3000 Hz.

Drawings

The present application will be further explained by way of exemplary embodiments, which will be described in detail by way of the accompanying drawings. These embodiments are not intended to be limiting, and in these embodiments like numerals are used to indicate similar structure, wherein:

fig. 1 is a block diagram illustrating the structure of a bone conduction headset according to some embodiments of the present application;

fig. 2 is a schematic longitudinal cross-sectional view of a bone conduction headset according to some embodiments of the present application;

FIG. 3 is a partial frequency response curve of a bone conduction headset according to some embodiments of the present application;

fig. 4 is a partial frequency response curve of a bone conduction headset when the housing of the bone conduction headset according to some embodiments of the present application is made of materials with different young's moduli;

fig. 5 is a graph of a partial frequency response of a bone conduction headset with different stiffness for a vibrating plate of the bone conduction headset according to some embodiments of the present application;

fig. 6 is a partial frequency response curve of a bone conduction headset having different stiffnesses for headset securing assemblies of the bone conduction headset according to some embodiments of the present application;

fig. 7A is a schematic diagram of a housing structure of a bone conduction headset according to some embodiments of the present application;

FIG. 7B is a graphical illustration of the frequency of higher order modes generated as a function of Young's modulus of the shell volume and material in accordance with some embodiments of the present application;

fig. 7C is a schematic diagram of the volume of a bone conduction speaker in relation to the volume of the housing according to some embodiments of the present application;

FIG. 8 is a schematic illustration of a housing shown in accordance with some embodiments of the present application to reduce leakage sound;

fig. 9 is a partial frequency response curve for a bone conduction headset having different housing weights according to some embodiments of the present application;

fig. 10A is a schematic structural diagram of a housing of a bone conduction headset according to some embodiments of the present application;

fig. 10B is a schematic structural diagram of a housing of a bone conduction headset according to some embodiments of the present application;

fig. 10C is a schematic structural view of a housing of a bone conduction headset according to some embodiments of the present application;

fig. 11 is a graph comparing the sound leakage effect of a conventional bone conduction headset and a bone conduction headset according to some embodiments of the present application;

fig. 12 is a frequency response curve generated by the housing faceplate of the bone conduction headset;

FIG. 13 is a schematic structural view of a housing panel according to some embodiments of the present application;

fig. 14A is a frequency response curve generated by the back of the housing of the bone conduction headset;

fig. 14B is a frequency response curve generated at the side of the housing of the bone conduction headset;

fig. 15 is a frequency response curve of a bone conduction headset produced by a housing bracket of the bone conduction headset;

fig. 16A is a schematic structural diagram of a bone conduction headset with a headset securing assembly according to some embodiments of the present application;

fig. 16B is a schematic structural diagram of another bone conduction headset with a headset securing assembly according to some embodiments of the present application;

fig. 17 is a schematic diagram of a housing structure of a bone conduction headset according to some embodiments of the present application;

fig. 18A is a schematic structural diagram of a vibration-transmitting patch of a bone-conduction headset according to some embodiments of the present application;

fig. 18B is a schematic structural diagram of a vibration-transmitting patch of another bone conduction headset according to some embodiments of the present application;

fig. 18C is a schematic structural diagram of a vibration-transmitting patch of another bone conduction headset according to some embodiments of the present application;

fig. 18D is a schematic structural diagram of a vibration-transmitting patch of another bone conduction headset according to some embodiments of the present application;

fig. 19 is a schematic structural diagram of a bone conduction headset with a stereo vibration conduction plate according to some embodiments of the present application;

fig. 20A is a schematic diagram of a bone conduction headset according to some embodiments of the present application;

fig. 20B is a schematic structural diagram of another bone conduction headset according to some embodiments of the present application;

fig. 20C is a schematic structural diagram of another bone conduction headset according to some embodiments of the present application;

fig. 20D is a schematic structural diagram of another bone conduction headset according to some embodiments of the present application;

fig. 21 is a schematic structural diagram of a bone conduction headset with sound introducing holes according to some embodiments of the present application;

fig. 22A-22C are schematic structural views of a bone conduction headset according to some embodiments of the present application;

fig. 23A-23C are schematic structural views of a bone conduction headset with a headset securing assembly according to some embodiments of the present application;

fig. 24 illustrates an exemplary method of measuring vibration of a bone conduction headset housing according to some embodiments of the present application;

FIG. 25 is an exemplary result measured in the manner shown in FIG. 24;

fig. 26 illustrates an exemplary method of measuring vibration of a bone conduction headset housing according to some embodiments of the present application;

FIG. 27 is an exemplary result measured in the manner shown in FIG. 26;

fig. 28 illustrates an exemplary method of measuring vibration of a bone conduction headset housing according to some embodiments of the present application; and

fig. 29 illustrates an exemplary method of measuring vibration of a bone conduction headset housing according to some embodiments of the present application;

Detailed Description

in order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings used in the description of the embodiments will be briefly introduced below. It is obvious that the drawings in the following description are only examples or embodiments of the application, from which the application can also be applied to other similar scenarios without inventive effort for a person skilled in the art. It is understood that these exemplary embodiments are given solely to enable those skilled in the relevant art to better understand and implement the present invention, and are not intended to limit the scope of the invention in any way. Unless otherwise apparent from the context, or otherwise indicated, like reference numbers in the figures refer to the same structure or operation.

As used in this application and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements. The term "based on" is "based, at least in part, on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". Relevant definitions for other terms will be given in the following description. Hereinafter, without loss of generality, in describing the bone conduction related art in the present invention, a description of "bone conduction speaker" or "bone conduction headset" will be employed. The description is merely one form of bone conduction application and it will be apparent to one of ordinary skill in the art that the "speaker" or "earpiece" may be replaced by other words of the same kind, such as "player", "hearing aid", etc. Indeed, various implementations of the invention may be readily applied to other non-speaker-type hearing devices. For example, it will be apparent to those skilled in the art that, having the benefit of the teachings of the bone conduction headset, various modifications and changes in form and detail may be made to the specific manner and procedure of implementing the bone conduction headset without departing from such teachings, and in particular, ambient sound pickup and processing functionality may be incorporated into the bone conduction headset to enable the headset to function as a hearing aid. For example, a microphone, such as a microphone, may pick up sounds from the user/wearer's surroundings and, under certain algorithms, transmit the sound processed (or resulting electrical signal) to a bone conduction speaker portion. That is, the bone conduction earphone may be modified to incorporate a function of picking up ambient sounds, and transmit the sounds to the user/wearer through the bone conduction speaker part after a certain signal processing, thereby implementing the function of the bone conduction hearing aid. By way of example, the algorithms described herein may include one or more combinations of noise cancellation, automatic gain control, acoustic feedback suppression, wide dynamic range compression, active environment recognition, active anti-noise, directional processing, tinnitus processing, multi-channel wide dynamic range compression, active howling suppression, volume control, and the like.

Fig. 1 is a block diagram illustrating a structure of a bone conduction speaker 100 according to some embodiments of the present application. As shown in fig. 1, the bone conduction speaker 100 may include a magnetic circuit assembly 102, a vibration assembly 104, a housing 106, and a connection assembly 108.

The magnetic circuit assembly 102 may provide a magnetic field. The magnetic field may be used to convert a signal containing acoustic information into a vibration signal. In some embodiments, the sound information may include video, audio files having a particular data format, or data or files that may be converted to sound through a particular pathway. The signal containing the sound information may come from a memory component of the bone conduction speaker 100 itself, or may come from an information generation, storage, or transmission system other than the bone conduction speaker 100. The signal containing acoustic information may include one or a combination of electrical, optical, magnetic, mechanical signals, and the like. The signal containing the sound information may be from one signal source or multiple signal sources. The multiple signal sources may or may not be correlated. In some embodiments, the bone conduction speaker 100 may acquire the signal containing the sound information in a number of different ways, the acquisition of the signal may be wired or wireless, and may be real-time or delayed. For example, the bone conduction speaker 100 may receive an electrical signal containing sound information in a wired or wireless manner, or may directly acquire data from a storage medium to generate a sound signal. For another example, a bone conduction hearing aid may include a component having a sound collection function, which picks up sound in the environment, converts mechanical vibration of the sound into an electrical signal, and obtains the electrical signal meeting specific requirements after processing by an amplifier. In some embodiments, the wired connection may include a metal cable, an optical cable, or a hybrid of metal and optical cables, such as a coaxial cable, a communications cable, a flex cable, a spiral cable, a non-metal sheathed cable, a multi-core cable, a twisted-pair cable, a ribbon cable, a shielded cable, a telecommunications cable, a twinax cable, a parallel twin-core wire, a twisted pair cable, or a combination of one or more thereof. The above-described examples are merely for convenience of illustration, and the medium for wired connection may be other types of transmission medium, such as other transmission medium of electrical or optical signals.

Wireless connections may include radio communications, free space optical communications, acoustic communications, electromagnetic induction, and the like. Wherein the radio communications may include the IEEE802.11 family of standards, the IEEE802.15 family of standards (e.g., Bluetooth and cellular technologies, etc.), first generation mobile communication technologies, second generation mobile communication technologies (e.g., FDMA, TDMA, SDMA, CDMA, and SSMA, etc.), general packet radio service technologies, third generation mobile communication technologies (e.g., CDMA2000, WCDMA, TD-SCDMA, and WiMAX, etc.), fourth generation mobile communication technologies (e.g., TD-LTE, FDD-LTE, etc.), satellite communications (e.g., GPS technologies, etc.), Near Field Communications (NFC), and other technologies operating in the ISM band (e.g., 2.4GHz, etc.); free space optical communication may include visible light, infrared signals, and the like; the acoustic communication may include acoustic waves, ultrasonic signals, etc.; electromagnetic induction may include near field communication techniques and the like. The above examples are for convenience of illustration only, and the medium for the wireless connection may be of other types, such as Z-wave technology, other premium civilian radio bands, and military radio bands, among others. For example, as some application scenarios of the present technology, the bone conduction speaker 100 may acquire signals containing sound information from other devices through bluetooth technology.

The vibration assembly 104 may generate mechanical vibrations. The generation of the vibration is accompanied by the conversion of energy, and the bone conduction speaker 100 can convert a signal containing sound information into mechanical vibration by using the magnetic circuit member 102 and the vibration member 104. The conversion process may involve the coexistence and conversion of multiple different types of energy. For example, the electrical signal may be directly converted to mechanical vibrations by a transducer device, producing sound. For another example, sound information may be included in the light signal, and a particular transducing device may effect the conversion of the light signal into a vibration signal. Other types of energy that may be co-present and converted during operation of the transducer device include thermal energy, magnetic field energy, and the like. The energy conversion mode of the energy conversion device can comprise moving coil type, electrostatic type, piezoelectric type, moving iron type, pneumatic type, electromagnetic type and the like. The frequency response range and sound quality of the bone conduction headset 100 may be affected by the vibration component 104. For example, in the moving coil transducer device, the vibrating element 104 includes a wound cylindrical coil and a vibrating body (e.g., a vibrating reed), the cylindrical coil driven by a signal current drives the vibrating body to vibrate and generate sound in a magnetic field, and the expansion and contraction of the vibrating body material, the deformation, size, shape, and fixing manner of the folds, the magnetic density of the permanent magnet, and the like all affect the sound effect quality of the bone conduction speaker 100. The vibrating body in the vibrating assembly 104 may be a mirror symmetric structure, a center symmetric structure, or an asymmetric structure; the vibrating body can be provided with a discontinuous hole-shaped structure, and the vibrating body generates larger displacement under the same input energy, so that the bone conduction speaker realizes higher sensitivity and improves the output power of vibration and sound; the vibrating body can be a torus or a torus-like structure, a plurality of supporting rods which converge towards the center are arranged in the torus, and the number of the supporting rods can be two or more. In some embodiments, the vibration assembly 104 may include a coil, a vibration plate, a vibration transmitting plate, and the like.

The housing 106 may transmit mechanical vibrations to the human body so that the human body can hear sounds. The housing 106 may form a closed or non-closed accommodating space, and the magnetic circuit assembly 102 and the vibration assembly 104 may be disposed inside the housing 106. The housing 106 may include an outer shell panel. The housing panel may be directly or indirectly connected to the vibration assembly 104 to transmit mechanical vibrations of the vibration assembly 104 to the auditory nerve via the bone, allowing the human body to hear sounds.

The linkage assembly 108 may provide connective support to the magnetic circuit assembly 102, the vibration assembly 104, and/or the housing 106. The connection assembly 108 may include one or more connectors. The one or more connectors may connect the housing 106 with one or more structures of the magnetic circuit assembly 102 and/or the vibration assembly 104.

The above description of the bone conduction speaker configuration is merely a specific example and should not be considered the only possible embodiment. It will be obvious to those having skill in the art that, having the benefit of the teachings of the present bone conduction speaker, it is possible to embody the bone conduction speaker in the specific manner and procedure with various modifications and changes in form and detail without departing from such teachings, but such modifications and changes are intended to be within the purview of the foregoing description. For example, the bone conduction speaker 100 may include one or more processors that may execute one or more sound signal processing algorithms. The sound signal processing algorithm may modify or enhance the sound signal. Such as noise reduction, acoustic feedback suppression, wide dynamic range compression, automatic gain control, active environment recognition, active anti-noise, directional processing, tinnitus processing, multi-channel wide dynamic range compression, active howling suppression, volume control, or the like, or any combination thereof, of the acoustic signal, and such modifications and variations are intended to be within the scope of the claims appended hereto. For another example, the bone conduction speaker 100 may include one or more sensors, such as a temperature sensor, a humidity sensor, a velocity sensor, a displacement sensor, and the like. The sensor may collect user information or environmental information.

Fig. 2 is a schematic diagram of a bone conduction headset 200 according to some embodiments of the present application. As shown in fig. 2, the bone conduction headset 200 may include a magnetic circuit assembly 210, a coil 212, a vibration-transmitting plate 214, a connector 216, and a housing 220.

The magnetic circuit assembly 210 may include a first magnetic element 202, a first magnetic permeable element 204, and a second magnetic permeable element 206. The magnetic element described in the present application refers to an element that can generate a magnetic field, such as a magnet or the like. The magnetic element may have a magnetization direction, which refers to a direction of a magnetic field inside the magnetic element. The first magnetic element 202 may include one or more magnets. In some embodiments, the magnet may comprise a metal alloy magnet, ferrite, or the like. Wherein the metal alloy magnet may comprise neodymium iron boron, samarium cobalt, alnico, iron chromium cobalt, aluminum iron boron, iron carbon aluminum, or the like, or combinations thereof. The ferrite may comprise barium ferrite, steel ferrite, manganese ferrite, lithium manganese ferrite, or the like, or various combinations thereof.

The lower surface of the first magnetic conductive element 204 may be connected to the upper surface of the first magnetic element 202. The second magnetic conductive element 206 may be a concave structure including a bottom wall and sidewalls. The second magnetic conductive element 206 may be connected to the first magnetic element 202 on the inside of the bottom wall, and the side wall may surround the first magnetic element 202 and form a magnetic gap with the first magnetic element 202. It should be noted that the magnetizer referred to herein may also be referred to as a magnetic field concentrator or an iron core. The magnetizer may adjust a distribution of a magnetic field (e.g., the magnetic field generated by the first magnetic element 202). The magnetizer may include a member processed from a soft magnetic material. In some embodiments, the soft magnetic material may include a metal material, a metal alloy, a metal oxide material, an amorphous metal material, and the like, such as iron, an iron-silicon based alloy, an iron-aluminum based alloy, a nickel-iron based alloy, an iron-cobalt based alloy, a low carbon steel, a silicon steel sheet, a ferrite, and the like. In some embodiments, the magnetizer may be processed by one or more combined methods of casting, plastic working, cutting working, powder metallurgy, and the like. The casting may include sand casting, investment casting, pressure casting, centrifugal casting, etc.; the plastic working may include one or more combinations of rolling, casting, forging, stamping, extruding, drawing, and the like; the cutting process may include turning, milling, planing, grinding, and the like. In some embodiments, the processing method of the magnetizer may include 3D printing, numerical control machine tool, and the like. The first magnetic conductive element 204, the second magnetic conductive element 206 and the first magnetic element 202 may be connected by one or more combinations of adhesion, clamping, welding, riveting, bolting, etc.

The coil 212 may be disposed in the magnetic gap between the first magnetic element 202 and the second magnetic conductive element 206. In some embodiments, the coil 212 may be energized with a signal current, and the coil 212 is in a magnetic field formed by the magnetic circuit assembly 210, and is subject to an ampere force, so that the coil 212 generates a mechanical vibration. While the magnetic circuit assembly 210 is subjected to a reaction force opposing the coil.

The vibration transfer plate 214 may have one end connected to the magnetic circuit assembly 210 and the other end connected to the case 220. In some embodiments, the vibration transfer plate 214 is a resilient member. The elasticity is determined by various aspects of the material, thickness, structure, etc. of the vibration-transmitting plate 214. The material of the vibration-transmitting plate 214 includes, but is not limited to, steel (such as, but not limited to, stainless steel, carbon steel, etc.), light alloy (such as, but not limited to, aluminum alloy, beryllium copper, magnesium alloy, titanium alloy, etc.), plastic (such as, but not limited to, high molecular weight polyethylene, blow-molded nylon, engineering plastic, etc.), and other single or composite materials capable of achieving the same performance. Composite materials may include, for example, but are not limited to, reinforcing materials such as glass fibers, carbon fibers, boron fibers, graphite fibers, graphene fibers, silicon carbide fibers, or aramid fibers, or composites of other organic and/or inorganic materials, such as various types of glass reinforced plastics composed of a matrix of glass fiber reinforced unsaturated polyester, epoxy, or phenolic resins. In some embodiments, the vibration-transmitting sheet 214 has a thickness of not less than 0.005mm, preferably, a thickness of 0.005mm to 3mm, more preferably, a thickness of 0.01mm to 2mm, still more preferably, a thickness of 0.01mm to 1mm, and further preferably, a thickness of 0.02mm to 0.5 mm. In some embodiments, the vibration transfer plate 214 may be an elastic structure, which means that the structure itself is an elastic structure, and even if the material is hard, the vibration transfer plate 214 itself has elasticity due to the elasticity of the structure itself. For example, the vibration-transmitting plate 214 may be formed as a spring-like elastic structure. In some embodiments, the structure of the vibration-transmitting plate 214 may be configured as a ring-like or ring-like structure, preferably, at least one ring, preferably, at least two rings, which may be concentric rings or non-concentric rings, and the rings are connected by at least two struts, the struts radiate from the outer ring to the center of the inner ring, further preferably, at least one elliptical ring, further preferably, at least two elliptical rings, different elliptical rings having different radii of curvature, and the rings are connected by struts, further preferably, the vibration-transmitting plate 214 comprises at least one square ring. The vibration-transmitting plate 214 may be configured as a plate, and preferably has a hollow pattern, and the area of the hollow pattern is not less than the area without the hollow. The materials, the thicknesses and the structures in the above description can be combined into different vibration transmission sheets. For example, the ring-shaped vibration-transmitting plates have different thickness distributions, preferably the strut thickness is equal to the ring thickness, further preferably the strut thickness is greater than the ring thickness, and further preferably the inner ring thickness is greater than the outer ring thickness. In some embodiments, the vibration plate 214 is partially attached to the magnetic circuit assembly 210 and partially attached to the housing 220, and preferably, the vibration plate 214 is attached to the first magnetically permeable element 204. In some embodiments, the vibration transfer plate 214 may be attached to the magnetic circuit assembly 210 and the housing 220 by glue. In some embodiments, the vibration plate 214 may be fixed to the housing 220 by welding, clamping, riveting, screwing (screws, bolts, etc.), interference fit, clamping, pinning, wedging, or forming.

In some embodiments, the vibration plate 214 may be coupled to the magnetic circuit assembly 210 by a coupling member 216. In some embodiments, the bottom end of the connector 216 may be fixed to the magnetic circuit assembly 210, for example, the connector may be fixed to the upper surface of the first magnetic conductive element. In some embodiments, the connector 216 has a top end opposite the bottom surface, and the top end can be fixedly connected to the vibration-transmitting plate 214. In some embodiments, the top end of the connector 216 may be glued to the vibration-transmitting plate 214.

The housing 220 has a housing panel 222, a housing back 224, and housing sides 226. The housing back surface 224 is located on the opposite side to the housing panel 222, and is provided on both end surfaces of the housing side surface 226, respectively. The housing panel 222, the housing back 224 and the housing side 226 form an integral structure having a receiving space. In some embodiments, the magnetic circuit assembly 210, the coil 212, and the vibration plate 214 are fixed inside the case 220. In some embodiments, the bone conduction headset 200 may further include a housing bracket 228, and the vibration transmitting plate 214 may be connected to the housing 220 through the housing bracket 228, and in some embodiments, the coil 212 may be fixed to the housing bracket 228 and vibrate the housing 220 through the housing bracket 228. Where the housing bracket 228 may be a portion of the housing 220 or may be a separate component that is directly or indirectly connected to the interior of the housing 220, in some embodiments, the housing bracket 228 is secured to the inner surface of the housing side 226. In some embodiments, the housing bracket 228 can be glued to the housing 220, or can be stamped, molded, snapped, riveted, screwed, or welded to the housing 220.

In some embodiments, the bone conduction speaker 100 further comprises an earphone fixing assembly (not shown in fig. 2). The earphone fixing component is fixedly connected with the shell 220, and keeps the bone conduction loudspeaker 100 stably contacted with human tissues or bones, so that the bone conduction loudspeaker 100 is prevented from shaking, and the earphone can stably transmit sound. In some embodiments, the earphone securing assembly may be an arcuate resilient member capable of creating a force that springs back toward the center of the arc. The two ends of the earphone fixing component are respectively connected with a shell 220, and the shells 220 at the two ends are kept in contact with human tissues or bones. For a more detailed description of the headset securing assembly, see the description elsewhere in this application, e.g., fig. 16 and related description.

Fig. 3 is a frequency response curve of a bone conduction speaker according to some embodiments of the present application. The horizontal axis represents the vibration frequency, and the vertical axis represents the vibration intensity of the bone conduction speaker 200. The vibration intensity referred to herein may be expressed as a vibration acceleration of the bone conduction speaker 200. In some embodiments, the flatter the frequency response curve, the better the sound quality exhibited by the bone conduction speaker 200 is considered to be, in the frequency response range of frequencies from 1000Hz to 10000 Hz. The structure of the bone conduction speaker 200, the design of the parts, the material properties, etc. may all have an effect on the frequency response curve. In general, low frequency refers to sound less than 500Hz, medium frequency refers to sound in the range of 500Hz-4000Hz, and high frequency refers to sound greater than 4000 Hz. As shown in fig. 3, the frequency response curve of the bone conduction speaker 200 may have two resonance peaks (310 and 320) in a low frequency region and a first high frequency valley 330, a first high frequency peak 340, and a second high frequency peak 350 in a high frequency region. Two resonance peaks (310 and 320) in the low frequency region may be generated for the vibrating plate 214 and the earphone fixing member to work together. The first high frequency valley 330 and the first high frequency peak 340 may be generated by the deformation of the case side 226 at a high frequency, and the second high frequency peak 350 may be generated by the deformation of the case panel 222 at a high frequency.

The positions of the different resonance peaks, high frequency peaks/valleys are related to the stiffness of the corresponding component. The stiffness is the ability of a material or structure to resist elastic deformation when subjected to a force. Stiffness is related to the young's modulus of the material itself and the dimensions of the structure. The greater the stiffness, the less the structure deforms under force. As mentioned above, the frequency response from 500Hz to 6000Hz is particularly critical for bone conduction speakers, and in this frequency range, sharp peaks and valleys are not desirable, and the flatter the frequency response curve, the better the sound quality of the earphone. In some embodiments, the peaks and valleys of the high frequency regions may be tuned to higher frequency regions by adjusting the stiffness of the housing panel 222 and the housing back 224. In some embodiments, the housing bracket 228 may also affect the peak-to-valley of the high frequency region. By adjusting the stiffness of the housing bracket 228, the peak-to-valley of the high frequency region can be adjusted to a higher frequency region. In some embodiments, the effective frequency band of the frequency response curve of the bone conduction speaker can be made to cover at least 500Hz to 1000Hz, or 1000Hz to 2000 Hz. More preferably, 500Hz to 2000Hz, more preferably, 500Hz to 4000Hz, more preferably, 500Hz to 6000Hz, more preferably, 100Hz to 10000 Hz. The effective band referred to herein means a band set according to a standard commonly used in the industry, for example, IEC and JIS. In some embodiments, no frequency width range in the active band exceeds 1/8 octaves, and the peak/valley magnitude exceeds the peak/valley of 10dB of average vibration intensity.

In some embodiments, the stiffness of the different components (e.g., the housing 220 and the housing bracket 228) is related to the Young's modulus, thickness, size, volume, etc. of their materials. Fig. 4 is a frequency response curve of a bone conduction speaker according to some embodiments of the present application when a housing of the bone conduction speaker is made of materials with different young's moduli. It is noted that, as previously described, the housing 220 may include a housing panel 222, a housing back 224, and housing sides 226. The housing face plate 222, the housing back 224, and the housing side 226 may be made of the same material or may be made of different materials. For example, the housing back 224 and the housing face 222 may be formed from the same material, and the housing sides 226 may be formed from other materials. In fig. 4, the housing 220 may be made of the same material as the housing panel 222, the housing back 224 and the housing side 226, so that the effect of the change of the young's modulus of the housing material on the frequency response curve of the bone conduction earphone can be clearly illustrated. From fig. 4, it can be seen that comparing the frequency response curves of the same size housing 220 made of three different materials with young's moduli of 18000MPa, 6000MPa and 2000 MPa: under the condition of unchanged size, the higher the Young's modulus of the material of the shell 220, the higher the rigidity of the shell 220, and the higher the frequency of the high frequency peak in the frequency response curve. The stiffness of the shell as referred to herein may be characterized by the modulus of elasticity of the shell, i.e., the change in shape of the shell that occurs when a force is applied to the shell. When the structure and size of the housing are fixed, the rigidity of the housing increases with the increase of the young's modulus of the material from which the housing is made. In some embodiments, the frequency response curve can be tuned at high frequencies to higher frequencies by adjusting the young's modulus of the housing 220 material. In some embodiments, the young's modulus of the material of the housing 220 may be greater than 2000MPa, preferably, the young's modulus of the material of the housing 220 may be greater than 4000MPa, preferably, the young's modulus of the material of the housing 220 is greater than 6000MPa, preferably, the young's modulus of the material of the housing 220 is greater than 8000MPa, preferably, the young's modulus of the material of the housing 220 is greater than 12000MPa, more preferably, the young's modulus of the material of the housing 220 is greater than 15000MPa, and even more preferably, the young's modulus of the material of the housing 220 is greater than 18000 MPa.

In some embodiments, by adjusting the stiffness of the housing 220, the high frequency peak frequency in the frequency response curve of the bone conduction headset may be not less than 1000Hz, preferably, the high frequency peak frequency may be not less than 2000Hz, preferably, the high frequency peak frequency may be not less than 4000Hz, preferably, the high frequency peak frequency may be not less than 6000Hz, more preferably, the high frequency peak frequency may be not less than 8000Hz, more preferably, the high frequency peak frequency may be not less than 10000Hz, more preferably, the high frequency peak frequency may be not less than 12000Hz, further preferably, the high frequency peak frequency may be not less than 14000Hz, further preferably, the high frequency peak frequency may be not less than 16000Hz, further preferably, the high frequency peak frequency may be not less than 18000Hz, further preferably, the high frequency peak frequency may be not less than 20000 Hz. In some embodiments, by adjusting the stiffness of the housing 220, the high frequency peak frequencies in the frequency response curve of the bone conduction headset may be outside the hearing range of the human ear. In some embodiments, the high frequency peak frequency in the frequency response curve of the earphone can be made to be within the hearing range of the human ear by adjusting the stiffness of the housing 220. In some embodiments, when there are multiple high frequency peaks/valleys, one or more high frequency peak/valley frequencies in the frequency response curve of the bone conduction headset may be outside the human hearing range and the remaining one or more high frequency peak/valley frequencies may be within the human hearing range by adjusting the stiffness of the housing 220. For example, the second high frequency peak 350 may be located outside the hearing range of the human ear, and the first high frequency valley 330 and the first high frequency peak 340 may be located within the hearing range of the human ear.

In some embodiments, the housing 220 may be designed to have a greater rigidity by designing the connection of the housing panel 222, the housing back 224, and the housing side 226. In some embodiments, the housing panel 222, the housing back 224, and the housing side 226 may be integrally formed. In some embodiments, the housing back 224 and the housing side 226 may be a unitary structure. The housing panel 222 and the housing side 226 may be fixed by glue directly or by clamping, welding or screwing. The glue can be a glue with strong viscosity and high hardness. In some embodiments, the housing panel 222 and the housing side 226 may be an integral structure, and the housing back 224 and the housing side 226 may be directly adhered and fixed by glue or fixed by clipping, welding or screwing. In some embodiments, the housing panel 222, the housing back 224, and the housing side 226 are separate components that can be fixedly connected by one or a combination of glue, snap, weld, or screw connections. For example, the housing face plate 222 and the housing side 226 may be attached by glue, and the housing back 224 and the housing side 226 may be attached by snap-fit, welding, or threaded connections. Or the housing back 224 and the housing sides 226 may be connected by glue, and the housing face 222 and the housing sides 226 may be connected by snap-fit, welding, or threaded connections.

In some embodiments, the overall stiffness of the housing 220 may be increased by selecting materials with the same or different young's moduli for the mating. In some embodiments, the housing panel 222, the housing back 224, and the housing sides 226 may all be made of one material. In some embodiments, the housing face plate 222, the housing back 224, and the housing sides 226 may be made of different materials, which may have the same young's modulus or different young's moduli. In some embodiments, the housing face plate 222 and the housing back face 224 are made of the same material, and the housing side faces 226 are made of other materials, and the Young's modulus of the two materials may be the same or different. For example, the young's modulus of the material of the housing sides 226 may be greater than the young's modulus of the material of the housing panels 222 and the housing back 224, or the young's modulus of the material of the housing sides 226 may be less than the young's modulus of the material of the housing panels 222 and the housing back 224. In some embodiments, the housing face plate 222 and the housing side 226 are made of the same material, and the housing back 224 is made of another material, and the Young's moduli of the two materials may be the same or different. For example, the young's modulus of the material of the housing back 224 may be greater than the young's modulus of the material of the housing panel 222 and the housing side 226, or the young's modulus of the material of the housing back 224 may be less than the young's modulus of the material of the housing panel 222 and the housing side 226. In some embodiments, the housing back 224 and the housing side 226 are made of the same material, and the housing face plate 222 is made of another material, and the Young's moduli of the two materials may be the same or different. For example, the young's modulus of the material of the housing panel 222 may be greater than the young's modulus of the material of the housing back 224 and the housing side 226, or the young's modulus of the material of the housing panel 222 may be less than the young's modulus of the material of the housing back 224 and the housing side 226. In some embodiments, the housing face plate 222, the housing back 224, and the housing side 226 are all different materials, and the young's moduli of the three materials may all be the same or all be different, and the young's moduli of the three materials are all greater than 2000 MPa.

Fig. 5 is a frequency response curve of a bone conduction headset when the vibration plates of the bone conduction headset have different stiffnesses, according to some embodiments of the present application. Fig. 6 is a frequency response curve of a bone conduction headset having different stiffnesses for headset securing assemblies of the bone conduction headset according to some embodiments of the present application. As can be seen from fig. 5 and 6, two resonance peaks in the low frequency region are associated with the vibration plate and the earphone-fixing member. The smaller the stiffness of the vibration transmitting plate 214 and the earphone fixing member, the more pronounced the response of the resonance peak at low frequencies. When the stiffness of the vibration transmitting plate 214 and the earphone fixing member is increased, the resonance peak is shifted toward the middle frequency or the high frequency, resulting in a deterioration of the sound quality. Therefore, when the vibration transmitting plate 214 and the earphone fixing member have low rigidity, the elasticity of the structure is better, and the sound quality of the earphone is better. In some embodiments, by adjusting the stiffness of the vibration transmitting plate 214 and the earphone fixing assembly, both of the peak frequencies of the low frequency region of the bone conduction earphone can be made less than 2000Hz, preferably both of the peak frequencies of the low frequency region of the bone conduction earphone can be made less than 1000Hz, and more preferably both of the peak frequencies of the low frequency region of the bone conduction earphone can be made less than 500 Hz. In some embodiments, the peak values of the two resonance peaks of the low frequency region of the bone conduction headset differ by no more than 150Hz, preferably the peak values of the two resonance peaks of the low frequency region of the bone conduction headset differ by no more than 100Hz, and more preferably the peak values of the two resonance peaks of the low frequency region of the bone conduction headset differ by no more than 50 Hz.

As described above, the present application can adjust the peak/valley of the high frequency region to a higher frequency and the low frequency resonance peak to a low frequency by adjusting the stiffness of each component of the bone conduction speaker (e.g., the housing bracket, the vibration transmission plate, or the earphone fixing component), thereby ensuring a frequency response curve platform in a range of 500Hz to 6000Hz and improving the sound quality of the bone conduction earphone.

On the other hand, the bone conduction speaker generates sound leakage during vibration transmission. The sound leakage refers to that the volume of the ambient air changes due to the vibration of the internal components of the bone conduction speaker 200 or the vibration of the housing, so that the ambient air forms a compressed area or a sparse area and is spread to the surroundings, and the sound is transmitted to the ambient environment, so that people except the wearer of the bone conduction headset can hear the sound emitted by the headset. This application can be from changing shell structure, angle such as rigidity, provides the solution that reduces bone conduction earphone sound leakage.

Fig. 7A is a schematic diagram of a housing structure of a bone conduction headset according to some embodiments of the present application. As shown in fig. 7, the housing 700 may include a housing panel 710, a housing back 720, and housing sides 730. The case panel 710 is in contact with the human body, and transmits the vibration of the bone conduction headset to the auditory nerve of the human body. In some embodiments, when the overall stiffness of the housing 700 is large, the amplitude and phase of the vibrations of the case panel 710 and the case back 720 remain the same or substantially the same over a range of frequencies (the case side 730 does not compress air and thus does not generate leakage), so that the first leakage signal generated by the case panel 710 and the second leakage signal generated by the case back 720 can be superimposed on each other. The superposition may reduce the amplitude of the first leakage sound wave or the second leakage sound wave, thereby achieving the purpose of reducing the leakage sound of the housing 700. In some embodiments, the certain frequency range includes at least a portion of frequencies greater than 500 Hz. Preferably, said certain frequency range comprises at least a portion of frequencies greater than 600 Hz. Preferably, said certain frequency range comprises at least a portion of frequencies greater than 800 Hz. Preferably, said certain frequency range comprises at least a portion of frequencies greater than 1000 Hz. Preferably, said certain frequency range comprises at least a part of frequencies above 2000 Hz. More preferably, said certain frequency range comprises at least a portion with a frequency greater than 5000 Hz. More preferably, said certain frequency range comprises at least a portion with a frequency greater than 8000 Hz. Further preferably, said certain frequency range comprises at least a part with a frequency above 10000 Hz. More description of the housing structure of the bone conduction headset may be found elsewhere in this application (e.g., fig. 22A-22C, and their associated description).

When the frequency exceeds a certain threshold, a particular portion of the housing 700 (e.g., the housing panel 710, the housing back 720, and the housing side 730) may vibrate to generate a higher order mode (i.e., a vibration inconsistency occurs at different points on the particular portion). In some embodiments, the housing volume and material of the housing 700 may be designed such that the frequencies that generate the higher order modes are higher. FIG. 7B is a graphical illustration of the relationship of frequencies that produce higher order modes to Young's modulus of the shell volume and material, according to some embodiments of the present application. For convenience of description, it is considered herein that different portions of the case 700 (e.g., the case panel 710, the case back 720, and the case side 730) are constructed of materials having the same young's modulus. It should be understood by those skilled in the art that different parts of the shell 700 may be formed by different poplarsSimilar results can still be obtained when the material is constructed of a material of a modulus (e.g., as shown in the examples elsewhere in this application). As shown in FIG. 7B, dashed line 712 represents the frequency of higher order modes generated by the enclosure 700 as a function of enclosure volume when the Young's modulus of the material is 15 GPa. Specifically, when the young's modulus of the housing material is 15GPa, the smaller the housing volume of the housing 700 is, the higher the frequency at which the higher-order mode is generated. For example, when the volume of the housing is 25000mm³The frequency of the higher-order modes generated by the shell 700 is about 4000Hz when the shell volume is 400mm³The frequency of the high order modes generated by the housing 700 is above 32000 Hz. Similarly, dashed line 713 shows the frequency of the higher order modes generated by the enclosure 700 as a function of enclosure volume when the Young's modulus of the enclosure material is 5 GPa. The solid line 714 represents the frequency of the higher order modes generated by the enclosure 700 versus the enclosure volume when the Young's modulus of the enclosure material is 2 GPa. It can be seen that the smaller the volume of the housing, the higher the young's modulus of the housing material, the higher the frequency of the high-order mode generated by the housing 700. In some embodiments, the volume of the housing 700 may be made 400mm³-6000mm ³While the Young's modulus of the housing material is between 2GPa and 18GPa, preferably the housing volume is 400mm³-5000mm ³While the Young's modulus of the housing material is between 2GPa and 10GPa, more preferably the housing volume is 400mm³-3500mm ³While the Young's modulus of the shell material is between 2GPa and 6GPa, and the volume of the shell is 400mm³-3000mm ³While the Young's modulus of the housing material is between 2GPa and 5.5GPa, and more preferably the housing volume is 400mm³-2800mm ³While the Young's modulus of the housing material is between 2GPa and 5GPa, more preferably the housing volume is 400mm³-2000mm ³While the Young's modulus of the casing material is between 2GPa and 4GPa, and further preferably the casing volume is 400mm³-1000mm ³While the young's modulus of the housing material is between 2GPa and 3 GPa.

It is to be appreciated that as the housing volume increases, a larger magnetic circuit system can be accommodated inside the housing 700, thereby providing a bone conduction speaker with increased sensitivity. In some embodiments, the sensitivity of the bone conduction speaker may be reflected by the volume level generated by the bone conduction speaker at a certain input signal. When the same signal is input, the greater the sound volume generated by the bone conduction speaker, the higher the sensitivity of the bone conduction speaker. Fig. 7C is a schematic diagram of the volume of a bone conduction speaker versus the volume of a housing according to some embodiments of the present application. As shown in fig. 7C, the abscissa represents the size of the volume of the housing, and the ordinate represents the volume level of the bone conduction speaker (in terms of the level relative to the reference volume, i.e., the relative volume) with the same input signal. The volume of the bone conduction speaker becomes larger as the volume of the housing increases. For example, when the volume of the case is 3000mm³When the relative volume of the bone conduction speaker is 1, when the volume of the casing is 400mm³The relative volume of the bone conduction speaker is between 0.25 and 0.5. In some embodiments, to make the bone conduction speaker have higher sensitivity (volume), the housing volume may be 2000mm³-6000mm ³Preferably, the housing volume may be 2000mm³-5000mm ³Preferably, the housing volume may be 2800mm³-5000mm ³Preferably, the housing volume may be 3500mm³-5000mm ³Preferably, the housing volume may be 1500mm³-3500mm ³Preferably, the housing volume may be 1500mm³-2500mm ³。

Fig. 8 is a schematic diagram of the case 700 for reducing leakage sound. As shown in fig. 8, when the bone conduction speaker is in an operating state, the housing panel 710 is in contact with a human body and mechanically vibrates. In some embodiments, the housing panel 710 may contact the skin of a person's face, causing some squeezing of the contacting skin, causing the skin at the perimeter of the housing panel 710 to protrude outward and deform. When the shell panel 710 vibrates, the shell panel moves towards the direction of a human face to squeeze the skin, the deformed skin on the periphery of the shell panel 710 is pushed to protrude outwards, and air around the shell panel 710 is compressed. When the shell panel moves away from the human face, a sparse area is formed between the shell panel 710 and the skin of the human face, and air around the shell panel 710 is absorbed. This compression and absorption of air results in a constant change in the volume of air surrounding the housing panel 710, causing the surrounding air to continuously form compressed or sparse areas and propagate around, transmitting sound to the surrounding environment, thereby creating sound leakage. If the rigidity of the housing 700 is large enough to allow the housing back 720 to vibrate with the housing panel 710 in the same direction and magnitude, when the housing panel 710 moves towards the face of a person, the housing back 720 moves towards the face of the person, and a sparse region of air is formed around the housing back 720, that is, when the air is compressed around the housing panel 710, the air is absorbed around the housing back 720. When the housing panel 710 moves away from the human face, the housing back 720 moves away from the human face, and a compression area of air is formed around the housing back 720, that is, when air is absorbed around the housing panel 710, the air is compressed around the housing back 720. The opposite effect of the back 720 and the front 710 of the housing on the air enables the bone conduction earphone to cancel the surrounding air, i.e., the external leakage noise can be cancelled, thereby achieving the effect of significantly reducing the leakage noise outside the housing 700. That is, the overall rigidity of the casing 700 can be improved to ensure that the casing back 720 and the casing panel 710 vibrate uniformly, and the casing side 720 does not push air and generate sound leakage, so that the sound leakage of the casing back 720 and the casing panel 710 can be cancelled, and the sound leakage outside the casing 700 can be greatly reduced.

In some embodiments, the rigidity of the casing 700 is high, so that the casing panel 710 and the casing back 720 can vibrate uniformly, and thus, the leakage sound outside the casing 700 can be cancelled out, and the purpose of reducing the leakage sound remarkably is achieved. In some embodiments, the housing 700 is more rigid and reduces sound leakage in the mid-low frequency range of the enclosure panel 710 and the enclosure back 720.

In one embodiment, increasing the stiffness of the housing 700 may be achieved by increasing the stiffness of the housing panel 710, the housing back 720, and the housing sides 730. The stiffness of the skin panel 710 is related to the Young's modulus, size, weight, etc. of the material. The greater the Young's modulus of the material, the greater the stiffness of the housing panel 710. In some embodiments, the young's modulus of the material of housing panel 710 is greater than 2000Mpa, preferably the young's modulus of the material of housing panel 710 is greater than 3000Mpa, the young's modulus of the material of housing panel 710 is greater than 4000Mpa, preferably the young's modulus of the material of housing panel 710 is greater than 6000Mpa, preferably the young's modulus of the material of housing panel 710 is greater than 8000Mpa, preferably the young's modulus of the material of housing panel 710 is greater than 12000Mpa, more preferably the young's modulus of the material of housing panel 710 is greater than 15000Mpa, and even more preferably the young's modulus of the material of housing panel 710 is greater than 18000 Mpa. In some embodiments, the housing panel 710 material includes, but is not limited to, Acrylonitrile Butadiene Styrene (ABS), Polystyrene (PS), High Impact Polystyrene (HIPS), Polypropylene (PP), Polyethylene terephthalate (PET), Polyester (PES), Polycarbonate (PC), Polyamide (PA), Polyvinyl chloride (PVC), Polyurethane (PU), Polyvinylidene chloride (PES), Polyethylene (PE), Polymethyl methacrylate (PMMA), polyether ether ketone (PEEK), phenolic resin (phenol, Urea), Melamine-formaldehyde resin (UF), and Melamine-formaldehyde resin (MF), and Melamine-formaldehyde resin (Melamine-formaldehyde resin, MF), and Melamine-formaldehyde resin (MF), and Polyethylene terephthalate (PVC), Polyurethane (PU), Polyvinyl chloride (PVC), Polyethylene (PE), Polymethyl methacrylate (PMMA), polyether ether ketone (PEEK), and Polyethylene-formaldehyde resin (PMMA) Scandium alloy, magnesium alloy, titanium alloy, magnesium-lithium alloy, nickel alloy, etc.), glass fiber, or carbon fiber, or a combination of any of the foregoing. In some embodiments, the material of the housing panel 710 is any combination of glass fiber, carbon fiber and Polycarbonate (PC), Polyamide (PA), or the like. In some embodiments, the housing panel 710 material may be a mixture of carbon fiber and Polycarbonate (PC) in a certain ratio. In some embodiments, the housing panel 710 may be made of a mixture of carbon fiber, glass fiber, and Polycarbonate (PC) in a certain ratio. In some embodiments, the housing panel 710 may be made of glass fiber mixed with Polycarbonate (PC) or Polyamide (PA). The rigidity of the obtained material is different by adding carbon fiber or glass fiber in different proportions. For example, 20 to 50 percent of glass fiber is added, and the Young modulus of the material can reach 4000 to 8000 MPa.

In some embodiments, the greater the thickness of the housing panel 710, the greater the stiffness of the housing panel 710. In some embodiments, the thickness of the housing panel 710 is no less than 0.3mm, preferably the thickness of the housing panel 710 is no less than 0.5mm, more preferably the thickness of the housing panel 710 is no less than 0.8mm, more preferably the thickness of the housing panel 710 is no less than 1 mm. However, as the thickness increases, the weight of the housing 700 also increases, thereby increasing the self weight of the bone conduction headset, resulting in the sensitivity of the headset being affected. Therefore, the thickness of the case panel 710 is not too large. In some embodiments, the thickness of the housing panel 710 is no more than 2.0mm, preferably, the thickness of the housing panel 710 is no more than 1.5mm, preferably, the thickness of the housing panel 710 is no more than 1.2mm, more preferably, the thickness of the housing panel 710 is no more than 1.0mm, more preferably, the thickness of the housing panel 710 is no more than 0.8 mm.

In some embodiments, the housing panel 710 may be provided in different shapes. For example, the housing panel 710 may be configured as a rectangle, an approximate rectangle (i.e., a racetrack shape, or a structure in which the four corners of the rectangle are replaced by arcs), an oval shape, or any other shape. The smaller the area of the housing panel 710, the greater the stiffness of the housing panel 710. In some embodiments, the area of the housing panel 710 is no greater than 8cm²Preferably, the area of the housing panel 710 is no more than 6cm²Preferably, the area of the housing panel 710 is no more than 5cm²More preferably, the area of the housing panel 710 is no more than 4cm²More preferably, the area of the housing panel 710 is no more than 2cm²。

In some embodiments, the stiffness of the housing 700 may be achieved by adjusting the weight of the housing 700. The heavier the weight of the housing 700, the greater the rigidity of the housing 700. However, the heavier the weight of the housing 700 is, the self weight of the earphone will increase, which affects the wearing comfort of the bone conduction earphone. And the heavier the weight of the case 700 is, the lower the sensitivity of the whole earphone becomes. Fig. 9 is a frequency response curve of a bone conduction headset according to some embodiments of the present application when the weight of the housing of the bone conduction headset is different. As shown in fig. 9, as the weight of the casing increases, the frequency response curve of the high frequency changes in the low frequency direction as a whole, and the frequency response curve of the headphone becomes peak/trough at the medium and high frequencies, resulting in deterioration of sound quality. In some embodiments, the weight of the housing 700 is less than or equal to 8 grams, preferably, the weight of the housing 700 is less than or equal to 6 grams, more preferably, the weight of the housing 700 is less than or equal to 4 grams, and even more preferably, the weight of the housing 700 is less than or equal to 2 grams.

In some embodiments, the stiffness of the housing panel 710 may be increased by simultaneously adjusting any combination of the young's modulus, thickness, weight, shape, etc. of the housing panel 710. For example, the desired stiffness can be obtained by adjusting the young's modulus and thickness. Or the desired stiffness can be obtained by adjusting young's modulus, thickness and weight. In some embodiments, the material of the housing panel 710 has a Young's modulus of not less than 2000MPa and a thickness of not less than 1 mm. In some embodiments, the material of the housing panel 710 has a Young's modulus of not less than 4000MPa and a thickness of not less than 0.9 mm. In some embodiments, the material of the housing panel 710 has a Young's modulus of not less than 6000MPa and a thickness of not less than 0.7 mm. In some embodiments, the material of the housing panel 710 has a Young's modulus of not less than 8000MPa and a thickness of not less than 0.6 mm. In some embodiments, the material of the housing panel 710 has a young's modulus of not less than 10000MPa and a thickness of not less than 0.5 mm. In some embodiments, the material of housing panel 710 has a Young's modulus of no less than 18000MPa and a thickness of no less than 0.4 mm.

In some embodiments, the housing may be any shape that is capable of vibrating together as a whole, and is not limited to the shape shown in fig. 7. In some embodiments, the housing may be any shape in which the projected areas of the housing panel and the housing back on the same plane are equal. In some embodiments, the shell 900 may be a cylinder, as shown in fig. 10A, the shell panel 910 and the shell back 930 are the upper end surface and the lower end surface of the cylinder, respectively, and the shell side 920 is the side of the cylinder. The projected areas of the housing face plate 910 and the housing back surface 930 on the cross section perpendicular to the axis on the column are equal. In some embodiments, the sum of the projected areas of the back of the housing and the sides of the housing is equal to the projected area of the panel of the housing. For example, the housing 900 may be approximately hemispherical, as shown in fig. 10B, the housing panel 910 may be a plane or a curved surface, the housing side 920 may be a curved surface (e.g., a bowl-shaped curved surface) with a plane parallel to the housing panel 910 as a projection plane, the housing back 920 may be a plane or a curved surface with a projection area smaller than that of the housing panel 910, and the sum of the projection areas of the housing side 920 and the housing back 930 is equal to that of the housing panel 910. In some embodiments, the projected area of the side of the housing facing the human body is equal to the projected area of the side of the housing facing away from the human body. For example, as shown in fig. 10C, the housing panel 910 and the housing back 930 are opposite curved surfaces, the housing side 920 is a curved surface that transitions from the housing panel 910 to the housing back, a portion of the housing side 920 is located on the same side as the housing panel 910, another portion of the housing side 920 is located on the same side as the housing back 930, and the sum of the projected areas of the portion of the housing side 920 and the housing panel 910 and the sum of the projected areas of the other portion of the housing side 920 and the housing back 930 is equal, taking the cross section with the largest cross-sectional area as a projection plane. In some embodiments, the difference in area of the housing panel and the housing back does not exceed 50% of the housing panel area, preferably the difference in area of the housing panel and the housing back does not exceed 40% of the housing panel area, more preferably the difference in area of the housing panel and the housing back does not exceed 30% of the housing panel area, more preferably the difference in area of the housing panel and the housing back does not exceed 25% of the housing panel area, more preferably the difference in area of the housing panel and the housing back does not exceed 20% of the housing panel area, more preferably the difference in area of the housing panel and the housing back does not exceed 15% of the housing panel area, more preferably the difference in area of the housing panel and the housing back does not exceed 12% of the housing panel area, more preferably the difference in area of the housing panel and the housing back does not exceed 10% of the housing panel area, more preferably, the difference in area between the housing panel and the housing back does not exceed 8% of the housing panel area, more preferably the difference in area between the housing panel and the housing back does not exceed 5% of the housing panel area, more preferably the difference in area between the housing panel and the housing back does not exceed 3% of the housing panel area, more preferably the difference in area between the housing panel and the housing back does not exceed 1% of the housing panel area, more preferably the difference in area between the housing panel and the housing back does not exceed 0.5% of the housing panel area, more preferably the areas of the housing panel and the housing back are equal.

Fig. 11 is a graph comparing the effect of leakage cancellation for a conventional bone conduction speaker and a bone conduction speaker according to some embodiments of the present application. The conventional bone conduction speaker is a bone conduction speaker formed by a housing made of a material with a conventional young's modulus. In fig. 11, the broken line is a leakage sound curve of the conventional bone conduction speaker, and the solid line is a leakage sound curve of the bone conduction speaker of the present application. The sound leakage of the traditional loudspeaker at low frequency is set to be 0, namely, a curve for sound leakage cancellation is drawn by taking the sound leakage cancellation of the traditional loudspeaker at low frequency as a reference. It can be seen that the leakage cancellation effect of the bone conduction speaker of the present application is significantly better than that of the conventional speaker. At low frequencies (e.g., less than 100 Hz), the effect of leakage cancellation is best, 40dB less leakage than conventional bone conduction speakers, with progressively weaker levels of leakage cancellation as the frequency increases, 20dB less leakage at 1000Hz than conventional bone conduction speakers, and only 5dB less leakage at 4000 Hz. In some embodiments, the comparison test result may be obtained by simulation. In some embodiments, the comparison test result may be obtained by a physical test. For example, the magnitude of the leakage sound may be measured by placing a bone conduction speaker in a quiet environment, inputting a signal current into the bone conduction speaker, and disposing a microphone in a space around the bone conduction speaker to receive a sound signal.

As can be seen from the results in fig. 11, at a low and medium frequency, the bone conduction speaker shell of the present application has a good vibration consistency, and can cancel most of the leakage sound, and the effect of reducing the leakage sound is significantly better than that of the conventional bone conduction headset. However, when high frequency vibration occurs, since it is difficult to keep the whole body to vibrate together, there is still serious sound leakage. On the other hand, at high frequencies, even if a material having a large young's modulus is used, the case is inevitably deformed. When the shell panel and the shell back are deformed and the deformations are not consistent (for example, the shell panel and the shell back can generate high-order modes at high frequency), the leakage sound generated by the two cannot be cancelled out, so that the leakage sound is caused. In addition, at high frequencies, the side surfaces of the housing are also deformed, which results in increased deformation of the housing panel and the housing back surface, and increased sound leakage.

Fig. 12 is a frequency response curve of a housing panel of a bone conduction speaker. At medium and low frequencies, the shell moves as a whole, and the shell panel and the shell back face vibrate in the same magnitude, speed and direction. At high frequencies, the shell panel exhibits higher-order modes (i.e., the vibration of the points on the shell panel is not uniform), and the shell also exhibits a distinct peak in the frequency response curve due to the presence of the higher-order modes (see fig. 12). In some embodiments, the young's modulus, weight, and/or size of the material of the housing panel may be adjusted to adjust the peak frequency. In some embodiments, the young's modulus of the material of the housing panel may be greater than 2000MPa, preferably, the young's modulus of the material may be greater than 4000MPa, preferably, the young's modulus of the material is greater than 6000MPa, preferably, the young's modulus of the material is greater than 8000MPa, preferably, the young's modulus of the material is greater than 12000MPa, more preferably, the young's modulus of the material is greater than 15000MPa, and even more preferably, the young's modulus of the material is greater than 18000 MPa. In some embodiments, the minimum frequency of the high-order modes appearing on the skin panel is not less than 4000Hz, preferably not less than 6000Hz, more preferably not less than 8000Hz, more preferably not less than 10000Hz, more preferably not less than 15000Hz, more preferably not less than 20000 Hz.

In some embodiments, by adjusting the stiffness of the enclosure panel, the peak frequency in the enclosure panel frequency response curve may be made greater than 1000Hz, preferably the peak frequency may be made greater than 2000Hz, preferably the peak frequency may be made greater than 4000Hz, preferably the peak frequency may be made greater than 6000Hz, more preferably the peak frequency may be made greater than 8000Hz, more preferably the peak frequency may be made greater than 10000Hz, more preferably the peak frequency may be made greater than 12000Hz, further preferably the peak frequency may be made greater than 14000Hz, further preferably the peak frequency may be made greater than 16000Hz, further preferably the peak frequency may be made greater than 18000Hz, further preferably the peak frequency may be made greater than 20000 Hz.

In some embodiments, the housing panels may be composed of one material. In some embodiments, the housing panels may be provided from a laminate of two or more materials. In some embodiments, the skin panel may be formed from a combination of a layer of material having a higher Young's modulus, plus a layer of material having a lower Young's modulus. The advantages are that the rigidity requirement of the shell panel is ensured, the comfort degree of the shell panel contacting with the human body is increased, and the contact matching degree of the shell panel and the human body is improved. In some embodiments, the material with a larger young's modulus may be Acrylonitrile-butadiene-styrene copolymer (ABS), Polystyrene (PS), High Impact Polystyrene (HIPS), Polypropylene (PP), Polyethylene terephthalate (PET), Polyester (Polyester, PES), Polycarbonate (PC), Polyamide (PA), Polyvinyl chloride (PVC), Polyurethane (PU), Polyvinylidene chloride (poly), Polyethylene (PE), Polymethyl methacrylate (PMMA), polyether ether ketone (PEEK), phenolic resin (phenol, Urea), Urea resin (PF), Melamine resin (UF), and Melamine resin (MF), aluminum alloy (UF), Melamine resin, MF), and Melamine resin (MF), such as aluminum alloy, Melamine resin, and Melamine resin (MF), such as aluminum alloy Scandium alloy, magnesium alloy, titanium alloy, magnesium-lithium alloy, nickel alloy, etc.), glass fiber, or carbon fiber, or a combination of any of the foregoing. In some embodiments, the material of the housing panel 710 is any combination of glass fiber, carbon fiber and Polycarbonate (PC), Polyamide (PA), or the like. In some embodiments, the material of the housing panel 710 may be a mixture of carbon fiber and Polycarbonate (PC) in a certain ratio. In some embodiments, the material of the housing panel 710 may be carbon fiber, glass fiber, and Polycarbonate (PC) mixed in a certain ratio. In some embodiments, the material of the housing panel 710 may be a mixture of glass fiber and Polycarbonate (PC) in a certain ratio. The rigidity of the obtained material is different by adding carbon fiber or glass fiber in different proportions. For example, 20 to 50 percent of glass fiber is added, and the Young modulus of the material can reach 4000 to 8000 MPa. In some embodiments, the material having a lower young's modulus may be silicone.

In some embodiments, the outer surface of the housing panel that contacts the human body may be a flat surface. In some embodiments, the outer surface of the housing panel may have protrusions or indentations, as shown in fig. 13, and the upper surface of the housing panel 1300 may have a protrusion 1310. In some embodiments, the outer surface of the housing panel may be a curved surface of any contour.

Fig. 14A is a frequency response curve of the back of the housing of the bone conduction speaker. The back of the shell vibrates consistently with the shell panel at medium and low frequencies, and at high frequencies, the back of the shell appears in a high-order mode. The high-order mode of the back of the shell can pass through the side face of the shell to influence the motion speed and the motion direction of the panel of the shell. At high frequencies, the deformation of the back of the housing can reinforce or cancel the deformation of the face of the housing, creating peaks and valleys at high frequencies. In some embodiments, a wider range of flatter frequency response curves may be obtained by adjusting the material and geometry of the back of the housing to have a higher peak frequency. Improve the tone quality of the bone conduction earphone. And reduces the sensitivity of the human ear to high frequency sound leakage, thereby reducing the sound leakage of the speaker. In some embodiments, the young's modulus, weight, and/or size of the material of the housing backplate can be adjusted to adjust the peak frequency of the occurrence of the housing back face. In some embodiments, the young's modulus of the material of the back side of the housing may be larger than 2000Mpa, preferably the young's modulus of the material may be larger than 4000Mpa, preferably the young's modulus of the material is larger than 6000Mpa, preferably the young's modulus of the material is larger than 8000Mpa, preferably the young's modulus of the material is larger than 12000Mpa, more preferably the young's modulus of the material is larger than 15000Mpa, further preferably the young's modulus of the material is larger than 18000 Mpa.

In some embodiments, by adjusting the stiffness of the back side of the housing, the peak frequency of the back side of the housing may be made greater than 1000Hz, preferably the peak frequency may be made greater than 2000Hz, preferably the peak frequency may be made greater than 4000Hz, preferably the peak frequency may be made greater than 6000Hz, more preferably the peak frequency of the back side of the housing may be made greater than 8000Hz, more preferably the peak frequency of the back side of the housing may be made greater than 10000Hz, more preferably the peak frequency of the back side of the housing may be made greater than 12000Hz, further preferably the peak frequency of the back side of the housing may be made greater than 14000Hz, further preferably the peak frequency of the back side of the housing may be made greater than 16000Hz, further preferably the peak frequency of the back side of the housing may be made greater than 18000Hz, further preferably the peak frequency of the back side of the housing may be made greater than 20000 Hz.

In some embodiments, the housing back may be comprised of one material. In some embodiments, the back of the housing may be provided by a laminate of two or more materials.

Fig. 14B is a frequency response curve of the housing side of the bone conduction headset. As mentioned above, the lateral surface of the housing itself does not cause sound leakage when vibrating at low frequencies. However, the side of the housing also affects the sound leakage of the speaker at high frequencies. The reason is that, at higher frequencies, the side faces of the housing are deformed, which causes the movement of the housing panel and the housing back to be inconsistent, so that the sound leakage from the housing panel and the housing back cannot be cancelled out, resulting in a larger sound leakage as a whole. Also, when there is deformation of the side of the housing, it causes a change in the bone conduction sound quality. As shown in fig. 14B, the frequency response of the side of the housing appears as peaks/valleys at high frequencies. In some embodiments, a wider range of flatter frequency response curves may be obtained by adjusting the material and geometry of the sides of the housing to have a higher frequency of peaks and valleys. Improve the tone quality of the bone conduction speaker. And reduces the sensitivity of the human ear to high frequency sound leakage, thereby reducing the sound leakage of the speaker. In some embodiments, the young's modulus, weight, and/or size of the material of the sides of the housing may be adjusted to adjust the frequency at which peaks/valleys occur. In some embodiments, the young's modulus of the material of the side of the housing may be larger than 2000Mpa, preferably the young's modulus of the material may be larger than 4000Mpa, preferably the young's modulus of the material is larger than 6000Mpa, preferably the young's modulus of the material is larger than 8000Mpa, preferably the young's modulus of the material is larger than 12000Mpa, more preferably the young's modulus of the material is larger than 15000Mpa, further preferably the young's modulus of the material is larger than 18000 Mpa.

In some embodiments, by adjusting the stiffness of the side of the housing, the peak frequency of the side of the housing may be made to be greater than 2000Hz, preferably the peak frequency of the side of the housing may be made to be greater than 4000Hz, preferably the peak frequency of the side of the housing may be made to be greater than 6000Hz, preferably the peak frequency of the side of the housing may be made to be greater than 8000Hz, more preferably the peak frequency of the side of the housing may be made to be greater than 10000Hz, more preferably the peak frequency of the side of the housing may be made to be greater than 12000Hz, more preferably the peak frequency of the side of the housing may be made to be greater than 14000Hz, more preferably the peak frequency of the side of the housing may be made to be greater than 16000Hz, more preferably the peak frequency of the side of the housing may be made to be greater than 18000Hz, and more preferably the peak frequency of the side of the housing.

In some embodiments, the housing sides may be comprised of one material. In some embodiments, the sides of the housing may be provided by a laminate of two or more materials.

The stiffness of the housing support may also affect the frequency response of the headset at high frequencies. Fig. 15 is a frequency response curve of a housing bracket of a bone conduction headset. As shown in fig. 15, at high frequencies, the housing bracket generates a resonance peak in the frequency response curve. The shell brackets with different rigidities have different resonance peak positions at high frequency. In some embodiments, the material and the geometric dimension of the housing bracket can be adjusted to enable the frequency of the resonance peak to be higher, so that the bone conduction speaker can obtain a flatter frequency response curve in a wider range at the middle and low frequencies, and the sound quality of the bone conduction speaker is improved. In some embodiments, the young's modulus, weight, and/or size of the material of the housing bracket may be adjusted to adjust the frequency at which the resonance peak occurs. In some embodiments, the young's modulus of the housing support material may be greater than 2000MPa, preferably, the young's modulus of the material may be greater than 4000MPa, preferably, the young's modulus of the material is greater than 6000MPa, preferably, the young's modulus of the material is greater than 8000MPa, preferably, the young's modulus of the material is greater than 12000MPa, more preferably, the young's modulus of the material is greater than 15000MPa, and even more preferably, the young's modulus of the material is greater than 18000 MPa.

In some embodiments, by adjusting the stiffness of the housing support, the peak frequency of the housing support may be made larger than 2000Hz, preferably the peak frequency of the housing support may be made larger than 4000Hz, preferably the peak frequency of the housing support may be made larger than 6000Hz, preferably the peak frequency of the housing support may be made larger than 8000Hz, more preferably the peak frequency of the housing support may be made larger than 10000Hz, more preferably the peak frequency of the housing support may be made larger than 12000Hz, further preferably the peak frequency of the housing support may be made larger than 14000Hz, further preferably the peak frequency of the housing support may be made larger than 16000Hz, further preferably the peak frequency of the housing support may be made larger than 18000Hz, further preferably the peak frequency of the housing support may be made larger than 20000 Hz.

In this application, through the young modulus and the size improvement casing of adjusting housing material the rigidity of casing, guarantee the uniformity of casing vibration for the sound leakage can superpose each other and cancel, reduces the sound leakage. And the peak frequency corresponding to different parts on the shell is adjusted to a higher frequency, so that the sound quality can be improved while the sound leakage is reduced.

Fig. 16A is a schematic diagram of a bone conduction speaker 1600 with a mounting assembly coupled to a housing according to some embodiments of the present application. As shown, a headset securing assembly 1620 is coupled to the housing 1610. The earphone fixing component 1620 can keep the bone conduction earphone in stable contact with human tissues or bones, so that the bone conduction earphone is prevented from shaking, and stable sound transmission of the earphone is ensured. As mentioned above, the earphone fixing component 1620 may be equivalent to a flexible structure, and when the stiffness of the earphone fixing component 1620 is smaller (i.e. the stiffness coefficient is smaller), the response of the resonance peak at the low frequency is more obvious, which is more beneficial to improve the sound quality of the bone conduction earphone. On the other hand, if the earphone holding member 1620 is low in rigidity (i.e., a small stiffness coefficient), vibration of the housing is facilitated.

Fig. 16B illustrates the manner in which the bone conduction speaker 1600 is connected between the earphone holding assembly 1620 and the housing 1610 via the connection component 1630. In some embodiments, the connecting member 1630 may be one or a combination of any number of silicone, sponge, and spring.

In some embodiments, the earphone fixing assembly 1620 may be in the form of a earhook, and a housing 1610 is connected to each end of the earphone fixing assembly 1620, respectively, to fix the two housings on two sides of the skull bone in an earhook manner. In some embodiments, the headset securing assembly 1620 may be a monaural ear clip. The earphone fixing assembly 1620 may be separately coupled to one housing 1610 and fix the housing 1610 to the skull side.

It should be appreciated that the above embodiments of the present application are merely examples or embodiments of the present application, and those skilled in the art can make appropriate adjustments according to different application scenarios of the present application. Further description of the connection of the headset securing assembly to the housing may be found elsewhere in this application (e.g., fig. 23A-23C, and related description).

Example one

As shown in fig. 17, the bone conduction speaker 1700 may include a magnetic circuit assembly 1710, a coil 1720, a connector 1730, a vibration plate 1740, a housing 1750, and a housing support 1760. In some embodiments, the bone conduction speaker 1700 further comprises a first element and a second element. The coil 1720 is connected to the housing 1750 via a first element. Magnetic circuit assembly 1710 is coupled to housing 1750 by a second element. The elastic modulus of the first member is greater than the elastic modulus of the second member. So as to realize the hard connection of the coil and the shell and the soft connection of the magnetic circuit component and the shell. The method achieves the purposes of adjusting the positions of the low-frequency resonance peak and the high-frequency resonance peak and optimizing the frequency response curve. In some embodiments, the first element may be a housing support 1760, the housing support 1760 being fixedly attached inside the housing 1750, and the coil 1720 being attached to the housing support 1760. The housing bracket 1760 is a ring bracket fixed to the inside wall of the housing 1750. The housing bracket 1760 is a rigid member and the housing bracket 1760 is made of a material having a Young's modulus greater than 2000 MPa. In some embodiments, the second element may be a vibration transfer sheet 1740. Magnetic circuit assembly 1710 is connected to vibration transfer plate 1740, which is an elastic member. The housing 1750 can be driven by the vibration transmitting piece 1740 to perform mechanical vibration, so that the vibration is transmitted to tissues and bones and is transmitted to auditory nerves through the tissues and the bones, and a human body can hear sound. The overall stiffness of the housing 1750 is relatively high, so that when the bone conduction headset 1700 works, the housing 1750 integrally vibrates together, that is, the shell panel, the shell side faces and the shell back face on the housing 1750 can keep basically the same vibration amplitude and phase, and the sound leakage outside the housing 1750 can be mutually superposed and cancelled, so that the external sound leakage is remarkably reduced.

Magnetic circuit assembly 1710 may include a first magnetic element 1706, a first magnetic permeable element 1704, a second magnetic element 1702, and a second magnetic permeable element 1708. The lower surface of the first magnetic permeable element 1704 may be connected to the upper surface of the first magnetic element 1706. The upper surface of the second magnetic permeable element 1708 may be connected to the lower surface of the first magnetic element 1706. The lower surface of the second magnetic element 1708 may be attached to the upper surface of the first magnetic permeable element 1704. The magnetization directions of the first magnetic element 1706 and the second magnetic element 1708 are opposite. The second magnetic element 1708 can suppress magnetic flux leakage at one side of the upper surface of the first magnetic element 1706, so that the magnetic field generated by the first magnetic element 1706 can be compressed into the magnetic gap between the second magnetic element 1708 and the first magnetic element 1706 to increase the magnetic induction intensity in the magnetic gap, thereby increasing the sensitivity of the bone conduction earphone 1700.

Similarly, a third magnetic element 1709 may be added to the lower surface of the second magnetic conductive element 1708, and the magnetization direction of the third magnetic element 1709 is opposite to the magnetization direction of the first magnetic element 1706, so as to suppress magnetic leakage at the lower surface side of the first magnetic element 1706, further compress the magnetic field generated by the first magnetic element 1706 into the magnetic gap, and improve the magnetic induction intensity in the magnetic gap and the sensitivity of the bone conduction speaker 1700.

The first magnetic element 1706, the first magnetic conductive element 1704, the second magnetic element 1702, the second magnetic conductive element 1708 and the third magnetic conductive element 1709 can be fixed by gluing. Holes may be punched in the first magnetic element 1706, the first magnetic conductive element 1704, the second magnetic element 1702, the second magnetic conductive element 1708, and the third magnetic conductive element 1709, and the holes may be fixed by screws.

Example two

Fig. 18A-18D are schematic diagrams of several configurations of vibration-transmitting sheets of bone conduction headphones. As shown in fig. 18A, the vibration-transmitting plate may include an outer ring and an inner ring, and a plurality of connecting rods disposed between the outer ring and the inner ring. The outer and inner rings may be concentric circles. The connecting rod may be an arc having a certain length. The number of connecting rods may be 3 or more. The inner ring of the vibration transmission piece can be fixedly connected with the connecting piece.

As shown in fig. 18B, the vibration transfer plate may include an outer ring and an inner ring, and a plurality of connecting rods disposed between the outer ring and the inner ring. The connecting rod may be a straight rod. The number of connecting rods may be 3 or more.

As shown in fig. 18C, the vibration plate may include an inner ring, and a plurality of bent rods radially distributed around and outwardly from the inner ring. The number of the bent rods may be 3 or more.

As shown in fig. 18D, the vibration-transmitting plate may be composed of a plurality of bent rods, one end of which is concentrated at the center point of the vibration-transmitting plate, and the other end of which is wound around the center point of the vibration-transmitting plate. The number of the bent rods may be 3 or more.

EXAMPLE III

Fig. 19 is a schematic diagram of a bone conduction speaker according to some embodiments of the present application. Bone conduction speaker 1900 may include magnetic circuit assembly 1910, coil 1920, vibrating plate 1930, housing 1940, and housing support 1950. Referring to fig. 17, in the structure of the first comparative example, the vibration plate in fig. 17 is a planar structure, and the vibration plate is located on a plane. The vibration plate in this embodiment has a three-dimensional structure, and as shown in fig. 19, the vibration plate 1930 has a three-dimensional structure in the thickness direction in a natural state where it is not subjected to a force. The size in the thickness direction of the bone conduction earphone 1900 can be reduced by using the three-dimensional vibration transmitting sheet. Referring to fig. 17, when the vibration plate is a planar structure, in order to ensure that the vibration plate can vibrate in the vertical direction during operation, a certain space needs to be reserved above and below the vibration plate. If the vibration-transmitting plate itself has a thickness of 0.2mm, a dimension of 1mm needs to be reserved above the vibration-transmitting plate, and a dimension of 1mm needs to be reserved below the vibration-transmitting plate, then a space of at least 2.2mm is required from the lower surface of the faceplate of the case 1940 to the upper surface of the magnetic circuit assembly. After the three-dimensional vibration transmission sheet is adopted, the vibration transmission sheet can vibrate in the thickness space of the vibration transmission sheet. The dimension of the three-dimensional vibration transmission plate in the thickness direction can be 1.5mm, and at the moment, the distance from the lower surface of the panel of the housing 1940 to the upper surface of the magnetic circuit assembly 1910 is only 1.5mm, so that the space of 0.7mm is saved. The size of the earphone 1900 in the thickness direction is greatly reduced. And the connecting piece can be eliminated, and the internal structure is simplified. On the other hand, when the housing using the three-dimensional vibration transmission plate has the same size as the housing using the vibration transmission plate having the planar structure, the three-dimensional vibration transmission plate may have a larger vibration amplitude than the vibration transmission plate having the planar structure, thereby increasing the maximum volume that the bone conduction speaker can provide.

The projected shape of the stereo resonator plate 1930 may be any one of the second embodiment.

In some embodiments, the outer edge of the volumetric vibrating plate 1930 may be connected to the inside of the housing bracket 1950. For example, when the seismic vibrator piece 1930 is in the configuration of a vibrator piece as shown in fig. 18A or 18B, its outer ring may be attached to the inside of the housing bracket 1950 by glue, snap-fit, welding, or threading. When the solid vibration transfer plate 1930 is in the vibration transfer plate configuration shown in fig. 18C or 18D, the bent rod surrounding the inner ring can be connected to the inside of the housing bracket 1950 by glue, snap-fit, welding, or screwing. In some embodiments, the housing bracket 1950 may have a plurality of slots, and the outer edge of the three-dimensional vibration transmitting plate 1930 may pass through the slots to be connected to the outside of the housing bracket 1950, and at the same time, the length of the vibration transmitting plate may be increased, which is beneficial to the change of the resonance peak to the low frequency direction, thereby improving the sound quality. The size of the slotted hole can provide enough space for the vibration of the vibration transmission piece.

Example four

Fig. 20A-20D are schematic diagrams of several bone conduction speakers according to some embodiments of the present application. As shown in fig. 20A, unlike the first embodiment, the speaker structure has no housing support, the first element is a connecting member 2030, and the coil 2020 is connected to the case 2050 through the connecting member 2030. The connecting member 2030 includes a columnar body, one end of which is connected to the case 2050, and the other end of which is provided with a circular end portion having a large sectional area and fixedly connected to the coil 2020. Connecting member 2030 is a rigid member made of a material having a young's modulus greater than 4000 Mpa. A washer may be connected between the coil 2020 and the connector 2030. The second element is a vibration transmitting plate 2040, the magnetic circuit assembly 2010 is connected with the vibration transmitting plate 2040, and the vibration transmitting plate 2040 is directly connected with the housing 2050. The vibration transmitting plate 2040 is an elastic member. The vibration conduction plate 2040 may be located above the magnetic circuit assembly 2010, and the vibration conduction plate 2040 may be connected to the upper end surface of the second magnetic conductive element 2008. The vibration conduction plate 2040 and the second magnetic conductive element 2008 may be connected by a gasket.

As shown in fig. 20B, unlike the structure of fig. 20A, the vibration conduction plate 2040 may be located between the second magnetic conductive element 2008 and the side wall of the housing 2050, and connected to the outside of the second magnetic conductive element 2008.

As shown in fig. 20C, the vibration conduction plate 2040 may be further disposed below the magnetic circuit assembly 2010 and connected to the lower surface of the second magnetic conductive element 2008.

As shown in fig. 20D, the coil 2020 is fixedly attached to the back of the housing by a connector 2030.

EXAMPLE five

As shown in fig. 21, the bone conduction speaker 2100 may include a magnetic circuit assembly 2110, a coil 2120, a connector 2130, a vibration transmitting plate 2140, a housing 2150, and a housing bracket 2160. The shell 2150 can be driven by the vibration transmission piece 2140 to vibrate mechanically, and transmit the vibration to the tissue and bone, and transmit the vibration to auditory nerve through the tissue and bone, so that the human body can hear the sound. The overall rigidity of the housing 2150 is high, so that when the bone conduction earphone 2100 works, the housing 2150 vibrates integrally, and external sound leakage can be canceled by each other and reduced significantly. The housing 2150 may be provided with a plurality of sound-inducing apertures 2151. The sound guide hole 2151 can transmit the leakage sound inside the earphone 2100 to the outside of the housing 2150, and the leakage sound outside the housing 2150 are mutually offset, so that the leakage sound of the earphone is further reduced. It is understood that vibration of the components inside housing 2150 also produces vibration of the air inside, thereby producing sound leakage. And the vibration of the internal parts and the vibration of the housing 2150 may be the same, so that a leakage sound in the direction opposite to the housing 2150 is generated, and the leakage sound of the housing 2150 can be cancelled each other, thereby reducing the leakage sound. The internal sound leakage required to be led out can be adjusted by adjusting the position, size and number of the sound leading holes 2151, so that the internal sound leakage and the external sound leakage can be cancelled, and the sound leakage is reduced. In some embodiments, the housing 2150 may have a damping layer at the location of the sound-emitting aperture 2151 to adjust the phase and amplitude of the emitted sound, thereby enhancing sound leakage cancellation.

EXAMPLE six

In different application scenarios, the housing of the bone conduction headset described in the present application may be made in different assembling manners. For example, as described elsewhere in this application, the housing of the bone conduction headset may be integrally formed, may be separately assembled, or may be a combination of the two. In the split combination mode, different splits can be fixed by glue or by clamping, welding or threaded connection. Specifically, fig. 22A-22C depict several examples of how the housing of the bone conduction headset may be assembled for better understanding of the manner in which the housing of the bone conduction headset is assembled in the present application.

As shown in fig. 22A, the housing of the bone conduction headset may include a housing panel 2222, a housing back 2224, and housing sides 2226. The housing side 2226 and the housing back 2224 are formed in an integral manner, and the housing panel 2222 is connected to one end of the housing side 2226 in a one-piece combination. The combination of the parts includes using glue to bond the parts together, or fastening the housing panel 2222 to one end of the housing side 2226 by snapping, welding or screwing. The housing panel 2222 and the housing side 2226 (or the housing back 2224) may be made of different, the same, or partially the same materials. In some embodiments, housing panel 2222 and housing sides 2226 are made of the same material, and the young's modulus of the same material is greater than 2000MPa, more preferably, the young's modulus of the same material is greater than 4000MPa, more preferably, the young's modulus of the same material is greater than 6000MPa, more preferably, the young's modulus of the housing 220 material is greater than 8000MPa, more preferably, the young's modulus of the same material is greater than 12000MPa, more preferably, the young's modulus of the same material is greater than 15000MPa, and even more preferably, the young's modulus of the same material is greater than 18000 MPa. In some embodiments, housing panel 2222 and housing sides 2226 are made of different materials that each have a young's modulus greater than 4000MPa, more preferably greater than 6000MPa, more preferably greater than 8000MPa, more preferably greater than 12000MPa, more preferably greater than 15000MPa, and even more preferably greater than 18000 MPa. In some embodiments, materials of housing panel 2222 and/or housing sides 2226 include, but are not limited to, Acrylonitrile Butadiene Styrene (ABS), Polystyrene (PS), High impact Polystyrene (High impact Polystyrene, HIPS), Polypropylene (PP), Polyethylene terephthalate (PET), Polyester (Polyester, PES), Polycarbonate (PC), polyamide (polyamide, PA), Polyvinyl chloride (PVC), Polyurethane (PU), Polyvinyl dichloride (Polyvinyl chloride), Polyethylene (Polyethylene, PE), Polymethyl methacrylate (PMMA), polyether ether ketone (PEEK), phenolic resin (phenol formaldehyde resin), Melamine formaldehyde resin (UF), and Melamine formaldehyde resin (UF), and Melamine formaldehyde resin (UF), Alloys (e.g., aluminum alloys, chromium molybdenum steel, scandium alloys, magnesium alloys, titanium alloys, magnesium lithium alloys, nickel alloys, etc.), glass fibers, or carbon fibers, or combinations thereof. In some embodiments, the material of the housing panel 710 is any combination of glass fiber, carbon fiber and Polycarbonate (PC), Polyamide (PA), or the like. In some embodiments, the material of the housing panel 2222 and/or the housing side 2226 may be carbon fiber and Polycarbonate (PC) mixed in a certain ratio. In some embodiments, the housing panel 2222 and/or the housing side 2226 may be made of a mixture of carbon fiber, glass fiber, and Polycarbonate (PC) in a certain ratio. In some embodiments, the housing panel 2222 and/or the housing side 2226 may be made of glass fiber and Polycarbonate (PC) mixed in a certain ratio, or may be made of glass fiber and Polyamide (PA) mixed in a certain ratio.

As shown in fig. 22A, the housing panel 2222, the housing back 2224, and the housing side 2226 form an integral structure having a certain accommodation space. Within the unitary structure, the vibration plate 2214 is connected to the magnetic circuit assembly 2210 by a connecting member 2216. The two sides of the magnetic circuit assembly 2210 are respectively connected with a first magnetic conductive element 2204 and a second magnetic conductive element 2206. The vibration-transmitting tab 2214 is secured to the interior of the unitary structure by a housing bracket 2228. In some embodiments, the housing sides 2226 have a stepped structure thereon for supporting the housing support 2228. After the housing support 2228 is fixed to the housing side 2226, the housing panel 2222 may be fixed to both the housing support 2228 and the housing side 2226, or may be fixed to either the housing support 2228 or the housing side 2226 separately. In this case, alternatively, the housing side 2226 and the housing holder 2228 may be integrally formed. In some embodiments, the housing bracket 2228 may be directly secured to the housing panel 2222 (e.g., by gluing, snapping, welding, screwing, etc.). The fixed housing panel 2222 and housing bracket 2228 are then fixed to the housing sides (e.g., by gluing, snapping, welding, or screwing). In this case, alternatively, the housing holder 2228 and the housing panel 2222 may be integrally formed.

As shown in fig. 22B, the difference from fig. 22A is that a housing support 2258 and a housing side 2256 are integrally formed. Housing panel 2252 is secured to housing side 2256 on one side to which housing brace 2258 is attached (e.g., by glue, snap, weld, or screw attachment), and housing back 2254 is secured to housing side 2256 on the other side (e.g., by glue, snap, weld, or screw attachment). In this case, optionally, the housing support 2258 and the housing side 2256 are formed as a separate assembly, and the housing panel 2252, the housing back 2254, the housing support 2258 and the housing side 2256 are fixedly connected by gluing, snapping, welding or screwing.

As shown in fig. 22C, the difference from fig. 22A and 22B is that the housing panel 2282 and the housing side 2286 are integrally formed. The housing back 2284 is secured to the housing side 2286 opposite the housing panel 2282 (e.g., by gluing, snapping, welding, threading, etc.). Housing support 2288 is secured to housing panel 2282 and/or housing sides 2286 by gluing, snapping, welding, or threading. In this case, optionally, the housing support 2288, the housing panel 2282, and the housing side 2286 are integrally formed structures.

EXAMPLE seven

As described elsewhere in this application, the housing of the bone conduction headset may be held in stable contact with human tissue or bone by the headset securing assembly. In different application scenarios, the earphone fixing component and the shell can be connected in different ways. For example, the earphone fixing component and the housing may be integrally formed, or may be separately combined, or may be combined with each other. In the split combination mode, the earphone fixing component can be adhered by glue or fixedly connected with a specific part on the shell in a clamping or welding mode. The specific part on the shell comprises a shell panel, a shell back and/or a shell side. In particular, fig. 23A-23C illustrate several examples of the connection of the housing of the bone conduction headset for a better understanding of the connection of the headset securing assembly to the housing in the present application.

As shown in fig. 23A, taking an ear hook as an example of the earphone fixing member, in addition to fig. 22A, an ear hook 2330 is fixedly connected to the housing. The fastening may include gluing, or snapping, welding, or screwing the ear clip 2330 onto the housing side 2326 or the housing back 2324. The portion of the ear clip 2330 that is attached to the housing can be made of the same, different, or part of the same material as the housing side 2326 or the housing back 2324. In some embodiments, plastic, silicone, and/or metal materials can also be included in the ear loop 2330 in order to provide the ear loop 2330 with less rigidity (i.e., less stiffness). For example, the ear clip 2330 can include a circular arc-shaped titanium wire. Alternatively, the ear clip 2330 can be integrally formed with the housing side 2326 or the housing back 2324.

As shown in fig. 23B, an ear hook 2360 is fixedly connected to the housing on the basis of fig. 22B. The fastening may include gluing, or snapping, welding, or threading the ear hook 2360 to the side 2356 or back 2354 of the housing. Similar to fig. 23A, the portion of the ear hook 2360 that is attached to the housing can be made of the same, different, or partially the same material as the housing side 2356 or the housing back 2354. Alternatively, the ear hook 2360 can be integrally formed with the housing side 2356 or the housing back 2354.

As shown in fig. 23C, an ear hook 2390 is fixedly connected to the housing on the basis of fig. 22C. The fixing connection mode comprises the step of adhering and fixing by using glue, or the ear hook 2390 is fixed on the side 2386 of the outer shell or the back 2384 of the outer shell in a clamping, welding or threaded connection mode. Similar to fig. 23A, the portion of the ear loop 2390 that is attached to the housing can be made of the same, different, or part of the same material as the housing side 2386 or housing back 2384. Optionally, the ear hook 2390 may be integrally formed with the housing side 2386 or the housing back 2384.

Example eight

As described elsewhere in this application, the stiffness of the housing of the bone conduction headset may affect the amplitude and phase of vibrations at different locations on the housing (e.g., the housing face plate, the housing back, and/or the housing sides), thereby affecting the leakage sound of the bone conduction headset. In some embodiments, when the housing of the bone conduction headset has a relatively large stiffness, the housing faceplate and the housing back can maintain the same or substantially the same amplitude and phase of vibration at higher frequencies, thereby significantly reducing sound leakage of the bone conduction headset.

The higher frequency referred to herein may include a frequency of not less than 1000Hz, for example, a frequency between 1000Hz-2000Hz, a frequency between 1100Hz-2000Hz, a frequency between 1300Hz-2000Hz, a frequency between 1500Hz-2000Hz, a frequency between 1700Hz-2000Hz, a frequency between 1900Hz-2000 Hz. Preferably, the higher frequency referred to herein may include a frequency of not less than 2000Hz, for example, a frequency between 2000Hz-3000Hz, a frequency between 2100Hz-3000Hz, a frequency between 2300Hz-3000Hz, a frequency between 2500Hz-3000Hz, a frequency between 2700Hz-3000Hz, or a frequency between 2900Hz-3000 Hz. Preferably, the higher frequency referred to herein may include a frequency of not less than 4000Hz, for example, a frequency between 4000Hz-5000Hz, a frequency between 4100Hz-5000Hz, a frequency between 4300Hz-5000Hz, a frequency between 4500Hz-5000Hz, a frequency between 4700Hz-5000Hz, or a frequency between 4900Hz-5000 Hz. More preferably, the higher frequency referred to herein may include a frequency of not less than 6000Hz, for example, a frequency between 6000Hz and 8000Hz, a frequency between 6100Hz and 8000Hz, a frequency between 6300Hz and 8000Hz, a frequency between 6500Hz and 8000Hz, a frequency between 7000Hz and 8000Hz, a frequency between 7500Hz and 8000Hz, or a frequency between 7900Hz and 8000 Hz. Further preferably, the higher frequency referred to herein may include a frequency of not less than 8000Hz, for example, a frequency between 8000Hz-12000Hz, a frequency between 8100Hz-12000Hz, a frequency between 8300Hz-12000Hz, a frequency between 8500Hz-12000Hz, a frequency between 9000Hz-12000Hz, a frequency between 10000Hz-12000Hz, or a frequency between 11000 Hz-12000 Hz.

The housing panel and the housing back face maintain the same or substantially the same vibration amplitude, which means that the ratio of the vibration amplitudes of the housing panel and the housing back face is within a certain range. For example, the ratio of the vibration amplitudes of the case panel and the case back is between 0.3 and 3, preferably, the ratio of the vibration amplitudes of the case panel and the case back is between 0.4 and 2.5, preferably, the ratio of the vibration amplitudes of the case panel and the case back is between 0.5 and 1.5, more preferably, the ratio of the vibration amplitudes of the case panel and the case back is between 0.6 and 1.4, more preferably, the ratio of the vibration amplitudes of the case panel and the case back is between 0.7 and 1.2, more preferably, the ratio of the vibration amplitudes of the case panel and the case back is between 0.75 and 1.15, more preferably, the ratio of the vibration amplitudes of the case panel and the case back is between 0.8 and 1.1, more preferably, the ratio of the vibration amplitudes of the case panel and the case back is between 0.85 and 1.1, and even more preferably, the ratio of the vibration amplitudes of the case panel and the case back is between 0.9 and 1.05. In some embodiments, the vibration of the housing panel and the housing back can be represented by other physical quantities that can characterize the amplitude of the vibration. For example, the sound pressure generated by the housing panel and the housing back at a point in space may be used to characterize the vibration amplitude of the housing panel and the housing back, respectively.

The case panel and the case back face maintain the same or substantially the same vibration phase as each other here means that the difference between the vibration phases of the case panel and the case back face is within a certain range. For example, the difference in the vibration phases of the case panel and the case back surface is between-90 ° and 90 °, preferably the difference in the vibration phases of the case panel and the case back surface is between-80 ° and 80 °, preferably the difference in the vibration phases of the case panel and the case back surface is between-60 ° and 60 °, preferably the difference in the vibration phases of the case panel and the case back surface is between-45 ° and 45 °, more preferably the difference in the vibration phases of the case panel and the case back surface is between-30 ° and 30 °, more preferably the difference in the vibration phases of the case panel and the case back surface is between-20 ° and 20 °, more preferably the difference in the vibration phases of the case panel and the case back surface is between-15 ° and 15 °, more preferably the difference in the vibration phases of the case panel and the case back surface is between-12 ° and 12 °, more preferably, the difference in vibration phase of the case panel and the case back is between-10 ° and 10 °, more preferably, the difference in vibration phase of the case panel and the case back is between-8 ° and 8 °, more preferably, the difference in vibration phase of the case panel and the case back is between-6 ° and 6 °, more preferably, the difference in vibration phase of the case panel and the case back is between-5 ° and 5 °, more preferably, the difference in vibration phase of the case panel and the case back is between-4 ° and 4 °, more preferably, the difference in vibration phase of the case panel and the case back is between-3 ° and 3 °, more preferably, the difference in vibration phase of the case panel and the case back is between-2 ° and 2 °, more preferably, the difference in vibration phase of the case panel and the case back is between-1 ° and 1 °, further preferably, the difference in the vibration phase of the case panel and the case back is 0 °.

Specifically, to better understand the relationship between amplitude and phase of vibrations of the housing faceplate and the housing back in this application, fig. 24-26 depict several examples of methods of measuring bone conduction headset housing vibrations.

As shown in fig. 24, the signal generating device 2420 may provide a driving signal to the bone conduction headset, so that the housing panel 2412 of the housing 2410 generates vibration. For the sake of brevity, a periodic signal (e.g., a sinusoidal signal) is described as the driving signal. The housing panel 2412 is driven by the periodic signal to perform periodic vibration. The range finder 2440 transmits a test signal 2450 (e.g., a laser) to the housing panel 2412, receives a signal reflected from the housing panel 2412, converts the signal into a first electrical signal, and transmits the first electrical signal to the signal testing device 2430. The first electrical signal (also referred to as a first vibration signal) may reflect a vibration state of the housing panel 2412. The signal testing device 2430 can compare the periodic signal generated by the signal generating device 2420 with the first electrical signal measured by the distance measuring device 2440, so as to obtain the phase difference (also referred to as the first phase difference) between the two signals. Similarly, the distance meter 2440 may measure a second electrical signal (also referred to as a second vibration signal) generated by vibration of the back surface of the housing, and obtain a phase difference (also referred to as a second phase difference) between the periodic signal and the second electrical signal by the signal testing device 2430. From the first phase difference and the second phase difference, a phase difference of the housing panel 2412 and the housing back surface can be obtained. Similarly, by comparing the magnitudes of the first and second electrical signals, the relationship of the vibration amplitudes of the housing panel 2412 and the housing back can be determined.

In some embodiments, a microphone may be used in place of rangefinder 2440. Specifically, it is possible to place microphones at positions near the housing panel 2412 and the housing back surface, respectively, measure sound pressures generated by the housing panel 2412 and the housing back surface, respectively, obtain signals similar to the above-described first electric signal and second electric signal, and determine the relationship between the amplitude and phase of vibration of the housing panel 2412 and the housing back surface based on this. It should be noted that when measuring the magnitude and phase of the sound pressure generated by the housing panel 2412 and the housing back, respectively, the microphones are preferably placed at a close distance (e.g., a vertical distance of less than 10mm) from the housing panel 2412 and the housing back, respectively, and are maintained at the same distance or at a similar distance from the housing panel 2412 and the housing back, respectively, which is the same as the corresponding positions of the housing panel 2412 and the housing back.

FIG. 25 is an exemplary result measured from FIG. 24. Wherein the abscissa represents time and the ordinate represents the magnitude of the signal. In the figure, the solid line 2410 represents the signal generated by the signal generating device 2420The periodic signal, dashed line 2520 represents the first electrical signal measured by the rangefinder. Amplitude of the first electrical signal, i.e. V₁And/2, the vibration amplitude of the shell panel can be reflected. The phase difference of the first electrical signal and the periodic signal may be expressed as:

wherein, t₁Representing the time interval, t, between adjacent peaks of said periodic signal and said first electrical signal₂Representing the period of the periodic signal.

Similarly, the amplitude of the second electrical signal may be obtained. The ratio of the amplitude of the first electrical signal to the amplitude of the second electrical signal may represent a ratio of the amplitude of vibration of the housing panel to the amplitude of vibration of the housing back. In addition, considering that there may be a phase difference of 180 ° between the first electrical signal and the second electrical signal when measuring (i.e., a measurement is performed by transmitting a test signal to the outer surfaces of the housing panel and the housing back, respectively), the phase difference of the second electrical signal and the periodic signal may be expressed as:

wherein, t₁' denotes the time interval between adjacent peaks of the periodic signal and the second electrical signal, t₂' denotes a period of the periodic signal.

And

the difference between the two can then reflect the phase difference between the housing face 2412 and the housing back.

It should be noted that when the vibration of the housing panel and the housing back are separately tested, the state of the test system should be kept as consistent as possible to avoid causing inaccuracy in the subsequently calculated phase difference. If the test system generates time delay during measurement, time delay compensation needs to be performed on the result of each measurement, or the delay of the test system is the same when the panel of the casing and the back of the casing are measured, so as to counteract the influence of the time delay.

Fig. 26 depicts another exemplary method of measuring bone conduction headset housing vibrations. The difference from fig. 24 is that fig. 26 includes two range finders 2640 and 2640'. The two distance meters may simultaneously measure vibrations of the case panel and the case back of the housing 2610 of the bone conduction headset and transmit a first electrical signal and a second electrical signal, which respectively reflect the vibrations of the case panel and the case back, to the signal testing device 2630. Likewise, the two rangefinders 2640 and 2640' may be replaced with two microphones, respectively.

FIG. 27 is an exemplary result measured from FIG. 26. In the figure, a solid line 2710 indicates a first electric signal reflecting the vibration of the panel of the housing, and a broken line 2720 indicates a second electric signal reflecting the vibration of the back of the housing. Amplitude of the first electrical signal, i.e. V₃And/2, the vibration amplitude of the shell panel can be reflected. Amplitude of said second electrical signal, i.e. V₄And/2, the vibration amplitude of the back of the shell can be reflected. In this case, the ratio of the vibration amplitudes of the case panel and the case back is V₃/V ₄. The phase difference between the first electrical signal and the second electrical signal, i.e., the phase difference between the vibrations of the housing panel and the housing back surface, may be expressed as:

wherein, t₃' denotes the time interval between adjacent peaks of the first and second electrical signals, t₄' denotes a period of the second signal.

Example nine

Fig. 28 and 29 depict an example of a method of measuring bone conduction headset housing vibration in the presence of a headset securing assembly.

Fig. 28 differs from fig. 24 in that the housing 2810 of the bone conduction headset is fixedly connected to a headset securing assembly 2860, for example, by any of the connection means described elsewhere in this application. The earphone fixing assembly 2860 is further fixed to the fixing device 2870 during the measurement. The fixture 2870 may maintain the portion of the earphone securing assembly 2860 to which it is attached in a stationary state. After the signal generating device 2820 provides the driving signal to the bone conduction headset, the housing 2810 as a whole may vibrate with respect to the vibrating device 2870. Similarly, the signal testing device 2830 may obtain the first electrical signal and the second electrical signal reflecting the vibration of the case panel and the case back, respectively, and determine the phase difference of the case panel and the case back based thereon.

Fig. 29 differs from fig. 26 in that the housing 2910 of the bone conduction headset is fixedly coupled to a headset securing assembly 2960, for example, by any of the coupling methods described elsewhere in this application. The earphone securing assembly 2960 is further secured to the securing device 2970 during the measurement. The securing device 2970 may hold the portion of the headset securing assembly 2960 to which it is attached stationary. After the signal generating device 2920 provides the drive signal to the bone conduction headset, the housing 2910 as a whole may vibrate relative to the fixation device 2970. Similarly, the signal testing device 2830 may simultaneously obtain the first electrical signal and the second electrical signal reflecting the vibrations of the case panel and the case back, and determine the phase difference of the case panel and the case back based thereon.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing disclosure is by way of example only, and is not intended to limit the present application. Various modifications, improvements and adaptations to the present application may occur to those skilled in the art, although not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present application and thus fall within the spirit and scope of the exemplary embodiments of the present application.

Also, this application uses specific language to describe embodiments of the application. Reference to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

Further, those skilled in the art will appreciate that aspects of the present application may be illustrated and described in terms of several patentable species or situations, including any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof. Accordingly, various aspects of the present application may be embodied entirely in hardware, entirely in software (including firmware, resident software, micro-code, etc.) or in a combination of hardware and software. The above hardware or software may be referred to as "data block," module, "" engine, "" unit, "" component, "or" system. Furthermore, aspects of the present application may be represented as a computer product, including computer readable program code, embodied in one or more computer readable media.

Additionally, the order in which elements and sequences of the processes are recited in the present application, the use of alphanumeric or other designations, is not intended to limit the order of the processes and methods in the present application, unless otherwise indicated in the claims. While various presently contemplated embodiments of the invention have been discussed in the foregoing disclosure by way of example, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.

Similarly, it should be noted that in the preceding description of embodiments of the application, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to require more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifiers "about", "approximately" or "substantially", etc. Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical data used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, numerical data should take into account the specified significant digits and employ a general digit preservation approach. Notwithstanding that the numerical ranges and data setting forth the broad scope of the range presented in some of the examples are approximations, in specific examples, such numerical values are set forth as precisely as possible within the practical range.

Finally, it should be understood that the embodiments described herein are merely illustrative of the principles of the embodiments of the present application. Other variations are also possible within the scope of the present application. Thus, by way of example, and not limitation, alternative configurations of the embodiments of the present application can be viewed as being consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to only those embodiments explicitly described and depicted herein.

Claims

A bone conduction speaker, comprising:

a magnetic circuit assembly for providing a magnetic field;

a vibration assembly, at least a portion of which is located in the magnetic field, converting an electrical signal input to the vibration assembly into a mechanical vibration signal; and

a case including a case panel facing a human body side and a case back side opposite to the case panel, the case accommodating the vibration member, the vibration member causing the case panel and the case back side to vibrate, the vibration of the case panel having a first phase, the vibration of the case back side having a second phase, wherein,

the absolute value of the difference between the first phase and the second phase is less than 60 degrees when the vibration frequency of the case panel and the vibration frequency of the case back are 2000Hz to 3000 Hz.
The bone conduction speaker of claim 1,

the vibration of the housing panel has a first amplitude and the vibration of the housing back has a second amplitude, and a ratio of the first amplitude to the second amplitude is in a range of 0.5 to 1.5.
The bone conduction speaker of claim 1, wherein vibration of the housing panel produces a first leakage sound wave and vibration of the housing back produces a second leakage sound wave, the first and second leakage sound waves overlapping each other, the overlapping reducing an amplitude of the first leakage sound wave.
The bone conduction speaker of claim 1,

the shell panel and the shell back are made of materials with Young modulus larger than 4000 Mpa.
The bone conduction speaker of claim 1,

the difference in area between the housing panel and the housing back does not exceed 30% of the housing panel area.
The bone conduction speaker of claim 1,

the bone conduction speaker further comprises a first element, wherein the vibration component is connected with the shell through the first element, and the Young modulus of the first element is larger than 4000 MPa.
The bone conduction speaker of claim 1,

the shell panel is connected with other parts of the shell through one or the combination of any more of glue, clamping, welding or threaded connection.
The bone conduction speaker of claim 1,

the housing panel and the housing back are made of a fiber reinforced plastic material.
The bone conduction speaker of claim 1,

the bone conduction speaker further comprises an earphone fixing component, and the earphone fixing component is used for keeping the bone conduction speaker in stable contact with a human body; and

the earphone fixing component is fixedly connected with the bone conduction loudspeaker through an elastic component.
The bone conduction speaker of claim 9,

the bone conduction speaker produces two low frequency resonance peaks in a frequency range of less than 500 Hz.
The bone conduction speaker of claim 10,

the two low frequency resonance peaks are related to the elastic modulus of the vibration component and the earphone fixing component.
The bone conduction speaker of claim 10,

and the two low-frequency resonance peaks generated in the frequency range smaller than 500Hz respectively correspond to the earphone fixing component and the vibration component.
The bone conduction speaker of claim 12,

the bone conduction speaker produces at least two high frequency resonance peaks in a frequency range greater than 2000Hz, the two high frequency resonance peaks being related to a modulus of elasticity of the housing, a volume of the housing, a stiffness of the housing panel, and/or a stiffness of the housing back.
The bone conduction speaker of claim 12,

the vibration component comprises a coil and a vibration transmission sheet;

at least a portion of the coil is located within the magnetic field and is driven in motion within the magnetic field by an electrical signal.
The bone conduction speaker of claim 14,

one end of the vibration transmission piece is in contact with the inner surface of the shell, and the other end of the vibration transmission piece is in contact with the magnetic circuit component.
The bone conduction speaker of claim 14,

the bone conduction speaker further comprises a first element, wherein the coil is connected with the housing through the first element, and the first element is made of a material with a Young modulus of more than 4000 MPa.
The bone conduction speaker of claim 16,

the bone conduction speaker further comprises a second member, wherein the magnetic circuit system is connected with the housing through the second member, and the elastic modulus of the first member is larger than that of the second member.
The bone conduction speaker of claim 17, wherein the second element is a vibration transfer plate, the vibration transfer plate being an elastic member.
The bone conduction speaker as claimed in claim 18, wherein the vibration conduction plate has a three-dimensional structure capable of mechanically vibrating in a thickness space thereof.
The bone conduction speaker of claim 1,

the magnetic circuit assembly comprises a first magnetic element, a first magnetic conductive element and a second magnetic conductive element;

the lower surface of the first magnetic conduction element is connected with the upper surface of the first magnetic element;

the upper surface of the second magnetic conduction element is connected with the lower surface of the first magnetic element;

the second magnetic conducting element is provided with a groove, the first magnetic element and the first magnetic conducting element are fixed in the groove, and a magnetic gap is formed between the first magnetic element and the side surface of the second magnetic conducting element.
The bone conduction speaker of claim 20,

the magnetic circuit assembly further comprises a second magnetic element;

the second magnetic element is arranged above the first magnetic conduction element, and the magnetization directions of the second magnetic element and the first magnetic element are opposite.
The bone conduction speaker of claim 21,

the magnetic circuit assembly further comprises a third magnetic element;

the third magnetic element is arranged below the second magnetic conduction element, and the magnetization directions of the third magnetic element and the first magnetic element are opposite.
A method of testing a bone conduction speaker, comprising:

sending a test signal to a bone conduction speaker, the bone conduction speaker comprising a vibration component and a housing containing the vibration component, the housing comprising a housing faceplate and a housing backplate located on either side of the vibration component, respectively, the vibration component causing vibration of the housing faceplate and the housing back based on the test signal;

acquiring a first vibration signal corresponding to vibration of the housing panel;

acquiring a second vibration signal corresponding to the vibration of the back of the shell; and

determining a phase difference of the vibration of the housing panel and the vibration of the housing back based on the first vibration signal and the second vibration signal.
The method of claim 23, wherein determining a phase difference of the vibration of the housing panel and the vibration of the housing back based on the first vibration signal and the second vibration signal comprises:

acquiring the waveform of the first vibration signal and the waveform of the second vibration signal; and

determining the phase difference based on a waveform of the first vibration signal and a waveform of the second vibration signal.
The method of claim 23, wherein determining a phase difference of the vibration of the housing panel and the vibration of the housing back based on the first vibration signal and the second vibration signal comprises:

determining a first phase of the first vibration signal based on the first vibration signal and the test signal;

determining a second phase of the second vibration signal based on the second vibration signal and the test signal; and

determining the phase difference based on the first phase and the second phase.
The method of claim 23,

the test signal is a sinusoidal periodic signal.
The method of claim 23, wherein obtaining a first vibration signal corresponding to vibration of the housing panel comprises:

emitting a first laser to an outer surface of the housing panel;

receiving first reflected laser light generated by reflecting the first laser light by the outer surface of the shell panel;

determining the first vibration signal based on the first reflected laser light.
The method of claim 23, wherein acquiring a second vibration signal corresponding to vibration of the back side of the housing comprises:

emitting a second laser light to an outer surface of the back side of the housing;

receiving second reflected laser generated by reflecting the second laser by the outer surface of the back surface of the shell;

determining the second vibration signal based on the second reflected laser light.
The method of claim 23, wherein the speaker further comprises:

a magnetic circuit assembly for providing a magnetic field, wherein at least a portion of the vibration assembly is positioned in the magnetic field to convert the test signal into a mechanical vibration signal.
The method of claim 23,

the loudspeaker also comprises an earphone fixing component, the earphone fixing component is connected with the loudspeaker through an elastic component, and the earphone fixing component is used for supporting the loudspeaker and enabling the shell to vibrate freely.
The method of claim 23,

the vibrations of the housing panel have a first phase and the vibrations of the housing back have a second phase;

the absolute value of the difference between the first phase and the second phase is less than 60 degrees when the vibration frequency of the case panel and the vibration frequency of the case back are 2000Hz to 3000 Hz.
The method of claim 31,

the vibration of the housing panel has a first amplitude and the vibration of the housing back has a second amplitude, and a ratio of the first amplitude to the second amplitude is in a range of 0.5 to 1.5.
The method of claim 31, wherein the vibration of the housing panel produces a first leakage sound wave and the vibration of the housing back produces a second leakage sound wave, the first and second leakage sound waves being superimposed on each other, the superimposition reducing the amplitude of the first leakage sound wave.
The method of claim 31,

the shell panel and the shell back are made of materials with Young modulus larger than 4000 Mpa.
The method of claim 33,

the difference in area between the housing panel and the housing back does not exceed 30% of the housing panel area.
The method of claim 31,

the loudspeaker further comprises a first element, wherein the vibration component is connected with the shell through the first element, and the Young modulus of the first element is larger than 4000 MPa.
The method of claim 23,

the shell panel is connected with other parts of the shell through one or the combination of any more of glue, clamping, welding or threaded connection.
The method of any one of claim 23,

the loudspeaker also comprises an earphone fixing component, and the earphone fixing component is connected with the loudspeaker through an elastic component;

the earphone fixing component and the back face of the shell or the side face of the shell are of an integrally formed structure.
The method of any one of claims 38,

the loudspeaker also comprises an earphone fixing component, and the earphone fixing component is connected with the loudspeaker through an elastic component;

the earphone fixing component is connected with the back face of the shell or the side face of the shell through one or a combination of any more of glue, clamping, welding or threaded connection.
A bone conduction speaker, comprising:

a magnetic circuit assembly for providing a magnetic field;

a vibration assembly, at least a portion of which is located in the magnetic field, converting an electrical signal input to the vibration assembly into a mechanical vibration signal;

a housing containing the vibration assembly; and

an earphone fixing assembly fixedly connected with the housing for maintaining the bone conduction speaker in contact with a human body, wherein,

the housing has a shell panel facing a side of a human body and a shell back opposite to the shell panel, and a shell side located between the shell panel and the shell back, the vibration assembly causing the shell panel and the shell back to vibrate.
The bone conduction speaker of claim 40,

the back surface of the shell and the side surface of the shell are of an integrally formed structure;

the shell panel is connected with the side face of the shell through one or the combination of any more of glue, clamping, welding or threaded connection.
The bone conduction speaker of claim 40,

the shell panel and the shell side face are of an integrally formed structure;

the back of the shell is connected with the side face of the shell through one or the combination of any more of glue, clamping, welding or threaded connection.
The bone conduction speaker of claim 40,

the bone conduction speaker further comprises a first element, wherein the vibration assembly is connected with the housing through the first element.
The bone conduction speaker of claim 43,

the side surface of the shell and the first element are of an integrally formed structure;

the shell panel is connected with the outer surface of the first element through one or the combination of any more of glue, clamping, welding or threaded connection;

the back of the shell is connected with the side of the shell through one or the combination of any more of glue, clamping, welding or threaded connection.
The bone conduction speaker of any one of claims 41-44,

the earphone fixing component and the back face of the shell or the side face of the shell are of an integrally formed structure.
The bone conduction speaker of any one of claims 41-44,

the earphone fixing component is connected with the back face of the shell or the side face of the shell through one or a combination of any more of glue, clamping, welding or threaded connection.
The bone conduction speaker of claim 40,

the shell is a cylinder, and the shell panel and the back of the shell are respectively the upper end surface and the lower end surface of the cylinder; and

the projected areas of the housing panel and the housing back surface on the cross section perpendicular to the axis of the column are equal.
The bone conduction speaker of claim 40,

the vibrations of the housing panel have a first phase and the vibrations of the housing back have a second phase;

the absolute value of the difference between the first phase and the second phase is less than 60 degrees when the vibration frequency of the case panel and the vibration frequency of the case back are 2000Hz to 3000 Hz.
The bone conduction speaker of claim 48,

the vibration of the housing panel and the vibration of the housing back include vibration having a frequency within 2000Hz to 3000 Hz.
The bone conduction speaker of claim 48,

the vibration of the housing panel has a first amplitude and the vibration of the housing back has a second amplitude, and a ratio of the first amplitude to the second amplitude is in a range of 0.5 to 1.5.
The bone conduction speaker of claim 48, wherein vibration of the housing panel produces a first leakage sound wave and vibration of the housing back produces a second leakage sound wave, the first and second leakage sound waves overlapping each other, the overlapping reducing the amplitude of the first leakage sound wave.
The bone conduction speaker of claim 48,

the shell panel and the shell back are made of materials with Young modulus larger than 4000 Mpa.
The bone conduction speaker of claim 51,

the bone conduction speaker further comprises a first element, wherein the vibration component is connected with the shell through the first element, and the Young modulus of the first element is larger than 4000 MPa.